CUT 1 medium spaghetti squash in half lengthwise. Place cut side down in a microwaveable dish with 1/4 cup (50 mL) water. Microwave on HIGH for 7 minutes; let stand. Repeat with other half. Scoop out cooked squash and place in a large casserole dish.

MEANWHILE, cook 1 cup (250 mL) each chopped onion, chopped parsley, sliced mushrooms and 1 can (28 oz/796 mL) drained diced tomatoes in 1/4 cup (50mL) KRAFT SIGNATURE Sundried Tomato & Oregano Dressing. Add vegetables to cooked squash. Stir in 1 cup (250mL) each grated KRAFT Mozzarella Cheese and KRAFT 100% Parmesan Grated Cheese.

TOP with additional Mozzarella cheese and bake at 400°F (200°C) for 30 minutes or until thoroughly heated.