Heat 2 tablespoons butter or oil in a saucepan over medium heat
Add 1 small chopped onion and cook until soft, if desired
Add 2 to 3 tablespoons tomato paste and cook for 1 to 2 minutes
Stir in 2 cups water or broth
Whisk until the tomato paste is fully dissolved
Add 1/2 teaspoon salt and 1/4 teaspoon black pepper
Add 1/2 teaspoon sugar, if desired
Simmer for 10 to 15 minutes
Stir in 1/4 cup milk, cream, or coconut milk, if desired
Taste and adjust seasoning
Serve hot