Heat the olive oil in a large, deep skillet or pot over medium-high heat. Add the sausage. Cook 4-5 minutes to brown. Stir often and break up larger pieces with a wooden spoon or spatula. Remove excess oil rendered if desired (see cook’s note).

Next, lower the heat to medium and add the diced onions. Cook for 2 minutes, stirring frequently.

Then, add the garlic, Italian seasoning, and pepper. Cook for 1 minute, stir often.

Add the pasta sauce and the diced tomatoes. Stir well and let the sauce come to a simmer. Then, lower the heat to medium-low, cover the skillet and cook the sauce for 30 minutes.

Keep the sauce at a simmer. Raise or lower the heat as needed and stir occasionally.

In the meantime, bring a large pot of water to a boil. Cook the tortellini following the package directions. Drain well.

Add the spinach a handful at a time to the sauce. Stir well until it wilts then add another handful.

Lastly, add the cooked tortellini to the sauce. Stir well to combine, cover, and let it warm for 5 minutes.

Serve with parmesan cheese, chopped fresh herbs, and crushed red pepper, if desired. Add a piece of crusty bread and a side salad for a delicious meal.