Cottage Potatoes

2 lbs. frozen hash brown potatoes
2 cups sour cream
1 can (10 3/4 oz.) cream of mushroom soup
2 cups Velveeta cheese, shredded or cubed
1/2 cup chopped onions
3/4 tsp. salt
1/4 tsp. pepper

Combine all ingredients except potatoes in large bowl; fold in potatoes. Spoon mixture into slow cooker or crockpot. Cover and cook on high for 1 1/2 hours; turn to low and cook 2 1/2 hours longer.