Ingredients:
- 1 lb lean ground beef
- 1/2 cup diced yellow onion
- 3 cloves minced garlic
- 1 tbsp olive oil
- 2 cups sugar-free marinara sauce
- 8 oz sliced pepperoni
- 1 cup sliced mushrooms
- 1 cup diced green bell pepper
- 2 cups shredded mozzarella cheese
- 1/4 cup grated parmesan cheese
- 1 tsp dried oregano
- 1/2 tsp red pepper flakes
Instructions:
- Heat olive oil in a skillet over medium-high heat.
- Add the ground beef and diced onion to the skillet. Cook until the beef is browned and the onions are translucent.
- Stir in the minced garlic and cook for an additional 60 seconds until fragrant.
- Transfer the browned beef mixture into the bottom of the slow cooker.
- Pour the sugar-free marinara sauce over the beef, stirring gently to combine.
- Layer the sliced mushrooms and diced green bell peppers evenly across the top of the beef mixture.
- Arrange the pepperoni slices in a single, overlapping layer over the vegetables.
- Top the casserole with shredded mozzarella cheese and grated parmesan cheese, then sprinkle with dried oregano and red pepper flakes.
- Cover and cook in the slow cooker on High for 4 hours or on Low for 8 hours.