Preheat oven to 350 degrees. Grease 4 ovenproof bowls/crocks for individual portions (or 1 small casserole dish, for family style).
Toast and butter the bread. Press one piece into the bottom of each bowl. Top with meat of choice. Use about 1/2 the cheese now to sprinkle over the meat.
Fry the potato slices lightly in a small amount of oil, flipping to brown both sides. Sprinkle with salt & pepper and layer on top of cheese.
Top potatoes with chopped scallions and sliced tomatoes. Sprinkle with remaining cheese. Press layers down, making a low spot in the center for the eggs.
Crack the eggs and carefully drop into low spot on the casserole. AVOID BREAKING THE YOLKS. Drizzle melted butter on the eggs and and sprinkle with salt & pepper. Put bowls on cookie sheet and bake approx. 12 minutes. Egg whites should be completely set. Serve while hot, right in bowls.