1. Heat oven to 350 degrees. 2. Heat butter and oil in large heavy skillet over medium heat. Add onions and leeks and cook, stirring occasionally, until lightly browned, 25 minutes. Stir in mustard and thyme and remove from heat. 3. Meanwhile, make croutons: toast bread squares on baking sheet in oven 10 minutes. 4. Heat half-and-half and milk in large saucepan over medium heat to simmering. Add onion mixture; reduce heat to simmer, stirring occasionally, 10 minutes. 5. Puree soup in batches in blender or food processor. Return to saucepan, season with salt and pepper, and heat gently. Garnish with croutons and serve hot. ---------------------------------------------------------------------------
Nutrition
Ingredients
