Heat oven to 350ºF.

Cut zucchini lengthwise in half; scoop out and discard centers, leaving 1/4-inch-thick shells.

Cook potatoes in hot oil in large skillet on medium heat 12 to 15 min., stirring occasionally.

Meanwhile, brown meat in another large skillet. Add onions, peppers and garlic; cook 3 min. Drain; stir in potatoes, 1/2 cup pasta sauce, seasoning and 1-1/2 cups cheese.

Mix 1/2 cup hot water and remaining pasta sauce; divide evenly onto bottoms of 2 (13x9-inch) baking dishes. Spoon about 1/2 cup meat mixture into each zucchini shell. Place stuffed zucchini in baking dishes; cover with foil. Bake 30 min.

Remove foil; sprinkle with remaining cheese. Bake 10 min. or until zucchini is tender.