Preheat: Preheat the oven to 375°F.
Brown the beef: Heat the olive oil in a large oven-safe skillet over medium-high heat. Add the onion and cook until softened, about 4-5 minutes Start Timer. Add the ground beef and cook, breaking it into small crumbles, until browned and cooked through. Drain any excess grease if needed.
1 Tbsp. olive oil, 1 small yellow onion, 1 lb. ground beef
Add seasonings: Stir in the garlic, Italian seasoning, garlic powder, salt, pepper, Worcestershire sauce, crushed red pepper flakes, and tomato paste. Cook for 1 minute Start Timer, stirring constantly, until fragrant.
4 cloves garlic, 1 tsp. kosher salt, 1/4 tsp. black pepper, 2 tsp. Italian seasoning, 1/2 tsp. garlic powder, 2 Tbsp. tomato paste, 1 tsp. Worcestershire sauce, 1/2 tsp. crushed red pepper flakes
Make the creamy sauce: Reduce the heat to medium-low. Stir in the marinara sauce. (Swirl some water around in the empty marinara jars to capture every bit of sauce, then pour it into the skillet.) Add the cubed cream cheese and stir until completely melted and smooth, about 3-5 minutes. Start Timer
2 (24 oz. jars) marinara sauce, 8 oz. full-fat cream cheese
Add the tortellini: Fold the refrigerated tortellini into the sauce until evenly coated.
1 (20 oz.) package refrigerated cheese tortellini
Assemble: Sprinkle evenly with the mozzarella and Parmesan. (If your skillet isn’t large enough, you can transfer this entire mixture to a greased oven-safe 9x13 casserole dish).
2 cups freshly shredded whole milk mozzarella cheese, 1/2 cup freshly grated Parmesan cheese
Bake: Cover loosely with foil and bake for 15-20 minutes Start Timer. Remove the foil and continue baking for 10-15 minutesStart Timer, or until the cheese is melted, bubbly, and lightly golden. Broil for 1-2 minutes Start Timer, if desired, for an extra golden, cheesy top. Let the casserole rest for 5-10 minutes before serving. Start Timer Garnish with fresh basil or parsley.
For garnish: 2 Tbsp. chopped fresh basil, or parsley, additional Parmesan cheese, chili flakes.