Creamy Zucchini Casserole

6 Tbsp butter
1 small onion, diced
3 medium zucchini, cut into 1/4-inch-thick slices
2 medium carrots, peeled and shredded
1 can (10 3/4 oz.) cream of chicken soup
1/2 cup sour cream
1 bag (8 oz.) herb-seasoned stuffing mix, coarsely crushed

Preheat oven to 350 degrees and grease a 13x9-inch glass baking dish. In a 12-inch skillet, melt butter over medium heat. Add onion and cook until tender but not browned, about 5 minutes, stirring occasionally. Add zucchini and carrots, and cook until zucchini is tender, about 8 minutes.

Remove skillet from heat; stir in undiluted cream of chicken soup and sour cream until evenly mixed. Sprinkle half of stuffing mix in baking dish. Spoon zucchini mixture on top, then remaining stuffing mix. Bake 25 to 30 minutes until hot and bubbly.