This cheeseburger inspired one pan casserole with quinoa is a cozy dinner with a protein and fiber boost from this sneaky hidden lentil trick. It has all the familiar flavors from the ground beef, cheddar cheese, pickles, lettuce, tomatoes, and burger sauce – but it’s a healthier option that cooks in a baking dish. {Gluten-Free Friendly / Dairy-Free Friendly}
I’m always looking for simple ways to make family dinners more filling and balanced, and adding lentils to ground beef is one of my favorite tricks. They blend right in, keep the texture hearty, and add extra fiber, plant-based protein, and budget-friendly volume without relying on more meat.
This recipe was inspired by my Mexican Quinoa Casserole, which has quickly become one of my most popular recipes. I’m on a mission to create casseroles that feel cozy and satisfying but still work as a well-balanced meal – with protein, fiber, veggies, and plenty of flavor in every serving.
Why I Love This Recipe
How to Make It
This casserole makes 6 servings. For a more “cheeseburger” feel, use a higher fat ground beef. If you want to make this lower in calories and “healthier”, stick to a leaner ground beef.
On its own, the baked casserole has a cozy, savory beef flavor, but the toppings are what really make it taste cheeseburger-inspired. Don’t skip the pickles, shredded lettuce, fresh tomatoes, and burger sauce if you want the full burger effect.
Ingredients
- 1 pound lean ground beef. I recommend 85/20 but 80/20 will definitely be more flavorful and taste more like a cheeseburger.
- 1 large white or yellow onion, diced.
- 2 bell peppers, diced, optional. I add them because I am all about a variety of produce with my meals. If you top the casserole with fresh tomatoes, lettuce and even avocado, then you could omit.
- 1 14.5 ounce can of petite diced tomatoes.
- 1 15.5 ounce can of lentils, rinsed, or about 1.75-2 cups cooked.
- 1 cup of uncooked pre-rinsed quinoa. If you are not using pre-rinsed, use a mesh lined strainer and rinse the quinoa.
- 1-1 1/2 cups of shredded cheddar cheese (or pepper jack would be good!).
- 1 teaspoon garlic powder.
- 1 teaspoon smoked paprika.
- 1 teaspoon pepper.
- 1 teaspoon salt.
For the Broth Mixture
- 1½ cups beef broth
- 3 tablespoons ketchup
- 1 tablespoon yellow mustard
- 2 teaspoons Worcestershire sauce
- 1 tablespoon garlic powder
- 1 tablespoon onion powder
- 1 tablespoon pickle juice
Optional Toppings
- Diced pickles
- Fresh diced tomatoes
- Shredded lettuce
- Green onions
- Sesame seeds
- Drizzle of burger sauce or homemade Greek Yogurt Big Mac Sauce (Lindsay Pleskot).
Directions
- Preheat oven to 400°F and dice the bell peppers into small pieces.
- Cook ground beef, onion, and bell peppers in a skillet until beef is browned and peppers are slightly softened. Season with salt, smoked paprika, garlic powder and pepper.
- Stir in lentils and mash them into the beef mixture using a potato masher. Add diced tomatoes with juices.
- In a bowl, whisk together broth, ketchup, Dijon, Worcestershire, garlic powder, onion powder, and optional pickle juice.
- Add quinoa to a greased 9×13 baking dish.
- Add beef/lentil mixture evenly over the casserole dish.
- Pour the broth/sauce mixture slowly and evenly over the whole casserole, especially around the edges and center, then gently press down with a spatula.
- Cover tightly with foil and bake for 40 minutes.
- Remove foil, then sprinkle with cheese so the entire top of the casserole is covered and bake uncovered for an additional 10 minutes. Then, broil on high for about two minutes to get the crustly cheesy topping!
- Let the casserole rest for 5–10 minutes before serving – this helps it thicken and set. Top with your favorite toppings – shredded lettuce, fresh tomatoes, pickles and special sauce!
To Store
Store in an airtight container for up to 4 days from when the groud beef was cooked or freeze (minus the toppings) for 3 months.
For meal prep, store the toppings separately and add them after reheating in the microwave.
Tips for Success
Use petite diced tomatoes for a less tomato-forward flavor
I recommend petite diced tomatoes for this recipe because they add moisture for the quinoa without turning the whole casserole into a tomato-based bake. Crushed tomatoes will work, but they make the casserole taste more tomato-forward. I first tested with crushed tomatoes and I learned this.
Cover tightly with foil
This is key. The quinoa cooks in the liquid while the casserole bakes, so you want to trap the steam. Make sure the foil is tightly sealed around the edges of the baking dish.
Don’t skip the resting time
Let the casserole sit for 10 minutes after baking. It will look a little loose at first, but it thickens as it cools and becomes much easier to scoop.
Add the toppings right before serving
The baked casserole base is cozy and savory, but the toppings are what bring in the cheeseburger flavor. Add shredded lettuce, diced pickles, fresh tomatoes, and burger sauce right before serving so everything stays fresh.
Season the beef well
Quinoa and lentils absorb a lot of flavor, so make sure the ground beef mixture is seasoned with salt and pepper. This helps prevent the casserole from tasting flat.
Frequently Asked Questions
Can I leave out the lentils?
Yes. You can leave them out, but they add fiber, plant-based protein, and help stretch the meal further. If omitting, the casserole may be a little less filling and slightly more loose depending on the liquid.
Can I use a different ground meat?
Yes. Ground turkey or ground chicken will work, but ground beef gives the most classic cheeseburger flavor. If using very lean meat, make sure to season well and don’t skip the cheese or toppings.
Do I need to cook the quinoa first?
No. The quinoa cooks directly in the casserole as long as it is covered tightly and has enough liquid. Use pre-rinsed quinoa or rinse it well before adding.
Why is my casserole watery after baking?
It may just need to rest. Let it sit for at least 10 minutes before serving. The quinoa and lentils will continue to absorb liquid as it cools.
Why is my quinoa still crunchy?
This usually happens if the foil wasn’t sealed tightly enough, the quinoa wasn’t evenly spread, or the casserole needed a little more time. Cover it again and bake for another 5–10 minutes, adding a splash of broth if it looks dry.
Can I make this ahead of time?
Yes. You can cook the beef mixture ahead of time and assemble before baking. For best texture, I’d wait to add the dry quinoa and liquid until right before baking.n I freeze this casserole?
What should I serve with it?
Honestly, it can stand alone as a complete meal, but it’s also good with a simple side salad, roasted vegetables, or extra burger toppings served “bowl style.”
Is This Casserole Gluten-Free?
This casserole is naturally gluten-free as long as you use gluten-free Worcestershire sauce, broth, ketchup, mustard, and toppings.
One Pan Cheeseburger Quinoa Casserole with Hidden Fiber Boost
Ingredients
- 16 ounces ground beef 85/20 recommended
- 1 cup pre-rinsed raw quinoa
- 1 large white onion, diced small
- 14.5 ounce can of petite diced tomatoes
- 15.5 ounce can of lentils, drained and rinsed sub with 2 cups cooked
- 2 bell peppers, diced small
- 1-1½ cups shredded cheddar cheese or preferred cheese pepper jack would be good
- 1 tablespoon onion powder
- 1 tablespoon garlic powder
- 1 teaspoon salt
- 1 teaspoon pepper
- 1 teaspoon smoked paprika
- 1½ cups beef bone broth or preferred liquid
- 3 tablespoons ketchup
- 1 tablespoon pickle juice
- 1 tablespoon yellow mustard
- 2 teaspoons Worcestershire sauce
- 1 tablespoon garlic powder
- 1 tablespoon onion powder
- Shredded lettuce
- Diced cherry tomatoes
- Sliced pickles
- Sesame seeds
- Greek Yogurt Big Mac Sauce
Method
- Preheat oven to 400°F and dice the bell peppers into small pieces.
- Cook ground beef, onion, and bell peppers in a skillet until beef is browned and peppers are slightly softened. Season with salt, smoked paprika, garlic powder and pepper.
- Stir in lentils and mash them into the beef mixture using a potato masher.
- Add diced tomatoes with juices.
- In a bowl, whisk together broth, ketchup, Dijon, Worcestershire, garlic powder, onion powder, and optional pickle juice.
- Add quinoa to a greased 9×13 baking dish.
- Add beef/lentil mixture evenly over the casserole dish.Pour the broth/sauce mixture slowly and evenly over the whole casserole, especially around the edges and center, then gently press down with a spatula.
- Cover tightly with foil and bake for 40 minutes.
- Remove foil, then sprinkle with cheese so the entire top of the casserole is covered and bake uncovered for an additional 10 minutes. Then, broil on high for about two minutes to get the crustly cheesy topping!
- Let the casserole rest for 5–10 minutes before serving – this helps it thicken and set. Top with your favorite toppings – shredded lettuce, fresh tomatoes, pickles and special sauce!
Notes
- Store in an airtight container in the fridge for up to 4 days or freeze (without toppings) for up to 3 months.
- Serve fresh lettuce and tomatoes when ready to consume and heat up the casserole prior to adding toppings for best results.
- Prep the beef mixture ahead of time so assembly is even faster on those busy nights!