1 1/2 pounds fresh white mushrooms, divided
1 large onion, quartered
1 large garlic clove
3 tablespoons olive oil, divided
1 3/4 cups Italian-flavored bread crumbs, divided
3 tablespoons grated Parmesan cheese
1 egg, lightly beaten
1/4 teaspoon ground black pepper
1 (17-ounce) jar meatless spaghetti sauce
1 (17-ounce) jar Alfredo sauce

Trim mushroom stems. In the container of a food processor, combine 1 pound (about 6 cups) of the mushrooms, the onion and garlic; pulse just until coarsely chopped. In a large skillet, heat 1 tablespoon of the oil until hot. Add mushroom mixture; cook and stir until mushrooms are tender and most of the liquid has evaporated, about 10 minutes. Remove from heat; spoon into a large bowl. Stir in 1 1/4 cups of the bread crumbs, the cheese, egg and pepper. Form into ten 3-inch long croquettes. Place remaining 1/2 cup bread crumbs on a plate or sheet of waxed paper; coat croquettes with bread crumbs. Slice remaining 1/2 pound mushrooms; set aside for later use. In a large skillet, over medium heat, heat 1 tablespoon of the oil until hot. Cook croquettes on both sides until browned, about 5 minutes. Meanwhile, in a medium skillet, over medium heat, heat remaining 1 tablespoon oil until hot. Add sliced mushrooms; cook and stir until tender, about 5 minutes. Stir in spaghetti sauce; cook until hot, about 2 minutes. Serve over croquettes. Sprinkle with Parmesan cheese, if desired.