In saucepan, break up frozen peas. Add buffer, mushrooms, water chestnuts, green onions, ginger, nutmeg and all but 1/4 cup chicken broth. Cover and simmer over low heat 6 to 8 minutes. In a cup, blend cornstarch and remaining 1/4 cup chicken broth. Stir until smooth. Stir into peas. Cook slowly, stirring constantly until liquid thickens and boils. Add salt, garlic salt and pepper. Simmer 2 or 3 minutes more. Serves 6 to 8.