Preheat oven to 375 degrees. Slice chiles and peppers into 3-inch julienne strips, toss together and set aside. Set 6 small or 1 large earthenware or glass casserole in the oven to heat thoroughly, about 10 minutes. Combine the cheeses in a bowl and place in the warm casseroles and return to the oven to cook for 5 minutes. Sprinkle the cheeses over the peppers and chiles and diced onion and return to the oven for 5-7 minutes longer or until cheese is completely melted and beginning to bubble. Sprinkle with freshly ground pepper and serve immediately with warmed flour tortillas and Green Salsa on the side.
In blender place tomatillos, jalapenos and water. Puree until just chunky. Add remaining ingredients and puree about 2 minutes more, or until no large chunks remain. This salsa keeps in the refrigerator, in a covered container, about 3 days.