Melt the butter in a large saucepan over medium-high heat. Add the garlic and saut? until fragrant, about 2 minutes. Add the broth and bring to a boil. Add the tortellini and cook halfway, about 5 minutes for frozen pasta, less if using fresh. Add the tomatoes and their liquid, reduce the heat to a simmer, and cook just until the pasta is tender. Stir in the spinach and basil and cook until wilted, 1 to 2 minutes. Serve sprinkled with the grated cheese.