Cheesy Mashed Potato Casserole

A great way of using boxed mashed potato mix. Thank you Holiday Cottage

2 teaspoons butter or margarine
8 medium green onions, sliced (1/2 cup)
1 medium yellow or orange bell pepper, chopped (1 cup)
3 cups hot water
1 cup half-and-half or whole milk
1/4 cup butter or margarine
1 box (7.2 oz) roasted garlic mashed potato mix (2 pouches)
1 1/2 cups shredded Cheddar cheese (6 oz)

• Heat oven to 350°F. Spray 2-quart casserole with cooking spray.
• In 10-inch nonstick skillet, melt 2 teaspoons butter over medium-high heat. 
• Cook onions and bell pepper in butter 1 minute, stirring occasionally. 
• Remove from heat; set aside.
• In 2-quart saucepan, heat water, half-and-half and 1/4 cup butter to boiling; remove from heat. 
• Stir in both pouches of potatoes and seasoning just until moistened. 
• Let stand about 1 minute or until liquid is absorbed. 
• Beat with fork until smooth.
• Spoon 1 1/3 cups of the potatoes into casserole 
• Top with half of the onion mixture and 3/4 cup of the cheese. 
• Spoon another 1 1/3 cups potatoes over cheese; carefully spread to cover. 
• Sprinkle evenly with remaining onion mixture. 
• Top with remaining potatoes; carefully spread to cover. 
• Sprinkle with remaining 3/4 cup cheese.
• Bake uncovered about 30 minutes or until hot.