Vegetable-Stuffed Shells with Creamy Cheese Sauce

Ingredients

• 1 (12-oz./340-g.) box jumbo pasta shells
• 1 large Spanish onion, finely diced
• oil, for sautéing
• 16 ounces (450 grams) mushrooms, finely diced
• 1 small eggplant, finely diced
• 1 small zucchini, finely diced
• 1 green pepper, finely diced
• 1 red pepper, finely diced
• 20–25 grape tomatoes, quartered
• 1 (6-oz./170-g.) can Gefen Tomato Paste
• 2 tablespoons brown sugar
• 1/2 teaspoon oregano
• 1/2 teaspoon garlic powder
• salt, to taste
• pepper, to taste
• 4 cups milk, divided
• 1 cup flour
• 1 teaspoon salt
• 1 and 1/2 cups shredded sharp cheddar cheese
• 3/4 teaspoons freshly ground Gefen Black Pepper