Melt 1 stick of butter in a glass measuring cup in the microwave, cutting it in pieces first. 50% power for 1 minute should work, depending on the power of your microwave
If you have time to thaw potatoes that is great, it can reduce your cook time. I often don't thaw them first, however. Combine the potatoes in the large mixing bowl with melted butter.
At this point, optionally add 2-3 cups of cooked ham, turkey sausage or boned chicken. Frozen peas may also be added. I always opt for ham.
Season with Creole seasoning and add onions, soup, sour cream and cheese. Blend thoroughly with a spatula or wooden spoon.
Pour into a greased (sprayed with nonstick cooking spray) 9 x 13" pyrex cooking dish. I sometimes have to put extra that won't fit into a second 8 x 8" pyrex.
Make crumb topping by melting 1/2 stick of butter and combining with crushed Corn Flakes.
Top potatoes with crumb topping.
Cook 1 hour and 15 minutes at 350 degrees F, uncovered, if starting with frozen potatoes. If thawed, you can reduce cooking time to 45 min or 1 hour. (Original recipe from mom called for 45 minutes.)
Allow it to cool a little before serving.