Preheat your oven to 350°F (175°C).

In an ovenproof skillet over medium-high heat, add the Italian sausage and cook for about 8-10 minutes until browned and cooked through.

In the same skillet, reduce the heat to medium and add sliced red and green bell peppers along with chopped onion. Sauté for about 5-7 minutes until tender.

Drain excess grease and pour in the beef broth, scraping the skillet to release browned bits. Simmer for about 2-3 minutes.

Whisk in heavy whipping cream, tomato paste, Italian seasoning, salt, and pepper, stirring well. Simmer for approximately 5 minutes.

Add grated parmesan cheese and stir until fully melted and the sauce is creamy.

Return sautéed sausage and veggies to the skillet, mixing them into the creamy sauce until coated evenly.

Sprinkle shredded mozzarella cheese over the mix, spreading it evenly across the top.

Place the skillet in the preheated oven and bake for 10-15 minutes until the mozzarella is melted and bubbly.

Remove from the oven, let cool for a few minutes, and serve.