1 (.35 oz.) pkg. dried porcini mushrooms
2/3 c. boiling water
6 to 7 medium-size zucchini (about 3 1/2 lb.)
6 tbsp. olive oil (as needed)
1 medium-size onion, chopped
2 ribs celery, chopped
1 lb. ground chuck
2 cloves garlic, chopped
2 oz. Prosciutto, chopped (about 1/2 c.)
1 c. bottled marinara sauce
1 tbsp. tomato paste
1 tsp. dried oregano
1 bay leaf
3/4 to 1 tsp. crushed red pepper flakes
1 c. grated Parmesan cheese

Heat oven to 450°F. Place dried mushrooms in small bowl. Cover with the boiling water. Let soak for 30 minutes or until the mushrooms have softened. Strain mushrooms, reserving liquid. Chop the mushrooms

Meanwhile, trim stem ends from zucchini; slice lengthwise about 1/4-inch thick.

Using 2 jelly roll pans and working in batches, brush 1 tablespoon oil over each pan. Place zucchini in single layer on pans. Roast in 450°F oven 20 minutes or until softened, turning over once. Repeat process with remaining zucchini slices, adding another 2 tablespoons oil, if needed.

Meanwhile, heat remaining 2 tablespoons oil in large skillet over medium heat. Add onion and celery; cook for about 12 minutes or until softened. Transfer to bowl.

Add ground chuck and garlic to skillet; cook over medium heat until browned, about 10 minutes. Add chopped mushrooms, reserved mushroom liquid, Prosciutto, marinara sauce, tomato paste, oregano, bay leaf and red pepper flakes. Add cooked onion mixture to skillet; simmer, uncovered, for 30 minutes. Remove bay leaf and discard. Reduce oven temperature to 350°F.

To assemble, spoon 1 1/3 cups of meat sauce over bottom of 13 x 9 x 2-inch glass baking dish. Top with half the zucchini slices. Sprinkle 1/3 cup Parmesan cheese over zucchini. Layer on top 1 1/3 cups meat sauce, remaining zucchini slices, 1/3 cup Parmesan, remaining 1 1/3 cups meat sauce and remaining grated Parmesan cheese.

Bake casserole in 350°F oven for 25 minutes or until heated through and cheese on top has lightly browned. Let stand for 5 minutes before serving.