Also tastes great made with crab meat.
Melt butter in skillet and saute onion, garlic, carrots, and parsley until soft. Cool. Stir mustard into fish stock in large bowl. Add lobster and sauteed vegetables. Puree in blender, several cups at a time. Return to bowl and add sour cream. Stir until blended. Thin with milk to desired consistency. Season with salt and pepper. Garnish with matchstick-size slivers of sweet red pepper.