The Best Funeral Potatoes

8 medium russet potatoes
1 can cream of chicken soup
2 c. sour cream
2 c. sharp Cheddar cheese
1/2 c. Parmesan cheese
1 small onion chopped
1 (4 oz.) can green chilies, drained (optional)
salt and pepper
1/4 c. butter softened
Crushed Cornflakes

Scrub 8 medium russet potatoes and cover with water in large pot. Cover and cook just until done. Do not overcook as they will get too mushy. If desired, peel before dicing, although it's good with the peel on too. Cut into small cubes or grate on large grater. In a sauce pan, sautee onion in butter. Mix in soup, sour cream and cheeses and chilies. Put grated potatoes into a 9 x 13 and sprinkle salt and pepper over all of them. Pour the sauce over and mix well in the baking dish. Sprinkle crushed cornflakes over the top. Bake at 375 for about 45 minutes.