Lightened Squash Casserole

INGREDIENTS

• 3 pounds yellow squash
• 1/2 cup chopped sweet onion
• 1 1/2 teaspoons salt, divided
• 1 cup grated carrots
• 1 (10 3/4-oz.) can reduced-fat cream of chicken soup
• 1 (8-oz.) container light sour cream
• 1/4 cup chopped fresh chives
• 1/2 cup crushed cornflakes cereal
• 1/2 cup crushed French fried onions
• 2 tablespoons melted butter
• 1/4 teaspoon freshly ground pepper