Over medium-high heat, in a heavy, medium nonstick skillet, heat 1 tsp oil. Add chopped sausage and saute until sausage is heated through, 2 to 3 minutes. Remove from heat and stir in cream cheese and 1/4 tsp pepper; mix well.
Brush both sides of mushrooms lightly with remaining olive oil. Place mushroom caps, cavity side up, on baking sheet sprayed with non-stick cooking spray. Fill each cavity with sausage mixture. Lightly sprinkle each with Parmesan.
Bake mushrooms in preheated oven for 7 to 8 minutes or until hot throughout. Sprinkle each with minced chives for garnish.
