Baked Ziti with Mushrooms, Peppers and Parmesan

This recipe is from Gourmet Magazine, and was presented by Sara Moulton on her FoodTV show, Sara's Secrets.  A sauce of cream, and pureed sweet peppers replaces the traditional tomato sauce usually found in baked ziti, and the results are fantastic.  I served this for dinner guests recently and it drew rave reviews.  Note that the recipe calls for yellow, orange and red bell peppers mostly for appearance, but any combination of them will work.  Do not, however, use green bell peppers.  Serves 8-10.

3 large	yellow bell peppers (about 1½ pounds), chopped
1 large	onion, chopped
3 cloves	garlic, minced
3 tablespoons	olive oil
1½ cups	heavy cream
1½ pounds	mushrooms, thinly sliced
2 medium	red bell peppers, cut into ¼" slices
2 medium	orange bell peppers, cut into ¼" slices
1 pound	ziti
1 bunch	scallions (green part only), thinly sliced
2 cups	freshly grated Parmesan (about 6 ounces)
Salt and pepper	to taste

Preheat the oven to 375 degrees.

Cook the ziti, according to package directions, until just done.  When the ziti is done reserve 1 cup pasta cooking water and drain ziti well in a colander.

While the ziti is cooking heat 1 tablespoon of the oil in a heavy saucepan and cook yellow peppers, onion, and garlic, covered, over moderately low heat, stirring occasionally, until peppers are soft, about 15 minutes.  Stir in cream. In a blender puree mixture in batches (use caution when blending hot liquids), transferring to a large bowl (large enough to hold all ingredients), and season with salt and pepper.

In a deep large heavy skillet, cook mushrooms and peppers in remaining 2 tablespoons oil over moderately high heat, stirring occasionally, until peppers are softened and most of liquid is evaporated, about 8 minutes.  Pour the mushroom mixture into the cream sauce, stirring to combine.

Add the ziti, scallion greens, 1½ cups Parmesan, reserved cooking water, and salt and pepper to taste, stirring until completely combined. Spoon mixture into a 3-quart shallow baking dish and sprinkle the top with remaining ½ cup Parmesan.

Bake ziti in middle of oven until hot and pasta begins to brown, about 20-30 minutes.