In small saucepan heat butter. Add mushrooms and cook for 3 to 4 minutes or until softened. Whisk in flour and cook for a couple of minutes to cook out the raw flour taste. Whisk in the tomato paste, then the liquid and bring to a simmer for a couple of minutes. Season with salt and pepper.
Stir in shrimp, cover and simmer a minute just until cooked through. Whisk in additional milk or heavy cream to adjust the consistency. Finish with chives, and adjust the seasoning. Spoon this over hot biscuits and serve with steamed snow or sugar snap peas.