Olive oil
12 lg. firm white mushrooms, stems removed & caps wiped clean
1 sm. lemon, halved
1/3 c. Parmesan or Romano cheese, freshly grated

FRESH BASIL PESTO:

2 c. fresh basil leaves, packed
2 lg. cloves garlic
1/2 c. pine nuts
3/4 c. Parmesan or Romano cheese, freshly grated
2/3 c. olive oil

Makes 1 1/2 cups: If using mortar and pestle, mince basil leaves finely. Transfer to mortar and crush to fine paste. Add garlic and work into paste. Gradually add pine nuts and crush until smooth. Blend in cheese. Add olive oil to mixture in slow steady stream, stirring constantly.

If using processor, combine basil and garlic in bowl and blend to fine paste. Add pine nuts and cheese and process until smooth. With machine running, pour olive oil through feed tube in slow steady stream and mix until smooth and creamy; if pesto is too thick, gradually pour up to 1/4 cup warm water through feed tube with machine running.

Transfer pesto to jar. Cover surface of pesto with film of olive oil about 1/8-inch thick. Seal jar with tight-fitting lid. Refrigerate up to 3 months, or freeze. Stir oil into pesto before using.

Brush bottom of baking dish with olive oil. Rub mushroom caps with olive oil. Rub mushroom caps with lemon to prevent darkening. Arrange rounded side down in a single layer in baking dish. Fill mushrooms with pesto. Sprinkle tops with about 2 1/2 tablespoons cheese. Drizzle small amount of olive oil over each. Bake until filling bubbles, 8 to 12 minutes. Sprinkle with remaining cheese and serve. Makes 6 servings.