Dawn's Kick-Butt Cheesy Potatoes

My friend, Dawn, made these potatoes for our Halloween party, and they were a big hit. I don't have a photo (too busy that night), but I do want to share the recipe.

1 red onion, diced
1/2 stick butter
2 bags hash browns
1 can cream of mushroom soup
1 can cream of chicken soup
1 cup shredded cheddar cheese
Vegetables (mushrooms, green pepper, broccoli) optional

Saute onions until soft. Put all in a crockpot and heat 4-6 hours on low (first hour on high) or bake in the oven.

If you bake it, add a topping.
Warning: This recipe is a beast on a crockpot (messy), but that's what dish soap and hot water are for, right?