Heat the butter in a large saucepan over medium-high heat.
Add the onions and garlic and cook, stirring often, until softened, 5 to 7 minutes.

Add the tomato puree, broth, 1/2 cup cream,thyme and
1/2 teaspoon each of salt and pepper. Simmer, stirring occasionally,
until slightly thickened, about 15 to 20 minutes.
Serve hot.