Mustard Caper

3 tablespoons butter
1/2 cup red wine or dry vermouth
2 tablespoons chopped green onions
1/2 cup water
1/2 cup heavy whipping cream
2 tablespoons capers
2 1/2 teaspoons prepared mustard
1 teaspoon salt
1/2 teaspoon coarsely ground black pepper
1 beef flavour bouillon cube or envelope
watercress for garnish

Melt butter in skillet. Add vermouth or wine and green onions. cook about 2 minutes, stirring to loosen brown bits on bottom of skillet. Stir in water, heavy cream, capers, prepared mustard, salt, pepper, and bouillon cube. Heat sauce to boiling.