Parboil a combination of peppers and squash, drain. Slice the vegetables lengthwise. Put one layer of vegetables on the bottom of casserole dish. Cover with a layer of Jack cheese (Cheddar is also good) - then another layer of each. Beat 2 eggs slightly; mix with 2 cups of milk and 1/2 cup flour, 1 teaspoon salt. Pour this liquid over the vegetables and cheese mixture. Bake at 350 degrees for 50 to 60 minutes, until set.