Trtellini with Tomato Cream Sauce

1 pkg frozen cheese tortellini
1 samll onion, chopped
2 tbsp olive oil
3 garlic cloves, minced
2 can diced tomatoes, undrained
1 pkg frozen chopped spinach, thawed and squeeze dry
1 1/2 tsp dried basil
1 tsp salt
1/2 tsp pepper
1 1/2 c heavy whipping cream
1/2 c grated parm cheese (addtl if you want as well)

Cook tortellini according to package directions. Meanwhile in large skillet saute onion in oil until tender. Add garlic, cook 1 min longer. Ad tomatoes, spinach, basil, salt and pepper. Cook and stir over medium heat unil liquid is absorbed, about 3 mins. Stir in cream and cheese. Bring to a boil, reduce heat and simmer uncovered for 8-10 mins until thickened. Drain tortellini and toss with sauce. Sprinkle with addtl cheese.