Shells with Spinach Pesto & Mushrooms

Pesto:
2 cups fresh spinach
1 cup fresh basil leaves
1/4 c. pine nuts
4 garlic cloves
1/3 cup olive oil

Combine spinach, basil, pine nuts and garlic in blender or food
processor; mix well.  Gradually add oil, blending until thickened.
Set aside.

Pasta:
1 box (16 oz.) pasta, prepared according to directions on box

Saute mixture:
2 Tbsp. olive oil
2 cups thinly sliced mushrooms
1/2 cup finely chopped onion
1/2 cup chopped red pepper
1/2 tsp. salt
1/2 tsp. ground black pepper

Heat oil in large skillet over medium-high heat.  Add mushrooms, onion
and red pepper.  Cook 4 to 5 minutes, stirring occasionally.  Season
with salt and pepper.

Add pesto and vegetable mixture to hot pasta.  Toss, adding hot water
to desired consistency.  Transfer to serving platter, top with 1/2 c.
parmesan cheese and 1/4 c. toasted pine nuts (optional).

(To toast pine nuts:  Heat in small saucepan over medium-high heat for
4-5 minutes, stirring occasionally.)