Preheat your oven to 350°F (175°C).
In a large skillet, heat the olive oil over medium heat. Add the sliced onions and cook, stirring occasionally, until they are caramelized, about 20 minutes.
While the onions are cooking, in another pan, brown the ground beef over medium heat until fully cooked. Drain any excess fat.
Add the butter to the caramelized onions, then stir in the rice, cooking for 2-3 minutes until the rice is lightly toasted.
Combine the cooked ground beef with the onion and rice mixture. Stir in the beef broth, dried thyme, salt, and pepper.
Transfer the mixture to a greased casserole dish. Cover with foil and bake in the preheated oven for 30 minutes.
Remove the foil, sprinkle the Gruyère cheese over the top, and return to the oven. Bake for an additional 10-15 minutes, or until the cheese is melted and bubbly.
Advertisement
Let the casserole cool for a few minutes before serving.
Variations & Tips
For a lighter version, you can substitute ground turkey or chicken for the ground beef. If you prefer a bit of spice, add a pinch of cayenne pepper or a few dashes of hot sauce to the beef mixture. For a gluten-free option, ensure your beef broth is gluten-free and consider using brown rice instead of white rice for added fiber. You can also add mushrooms to the caramelized onions for an earthy flavor, or top the casserole with crispy fried onions for extra crunch.
ADVERTISEMENT
