In a large skillet, heat oil over medium-high heat. Add onion; cook and stir until tender, 2-3 minutes. Add garlic; cook 1 minute longer. Add tomatoes, spinach and seasonings. Cook and stir over medium heat until liquid is absorbed, about 3 minutes., Stir in cream; bring to a boil. Reduce heat; simmer, uncovered, until thickened, about 10 minutes. Meanwhile, cook tortellini according to package directions; drain. Stir into sauce. Sprinkle with cheese.