Step 1 In a large saute pan over medium heat, cook the onions and garlic until the onion is translucent, 3 to 5 minutes.
Step 2 Stir in the tomato puree and chipotle pepper and bring to a simmer over medium heat. Continue to cook for 15 minutes, stirring occasionally, to allow the flavors to blend and the sauce to reduce slightly; lower the heat if the bottom of the pan gets too hot so the sauce doesn't burn.
Step 3Remove the pan from the heat and whisk in the cream, then set aside. Makes about 1 1/4 cups sauce.