A delicious casserole.I like to use the Ro-tel tomatoes with MILD green chilies. If you like hot, by all means use hot. Also, I like to mix the diced tomatoes and the ro-tel tomatoes in a blender for just a few seconds to break up the tomatoes a bit but, this is not necessary. I just like my tomatoes broken down a little more to a saucy texture. I have used PLAIN yogurt instead of sour cream, which is equally good. Same with the cheeses, Mozzarella or Monterey Jack-both good. This is one of those dishes that the left overs taste great the next day!