Baked Eggs With Herbs without water yolks garlic

1 small round loaf crusty bread, 2 ends removed, the rest cut into 4 thick slices (about 10 ounces) 3/4 lb asparagus , tough ends snapped off and discarded,[...]

1 small onion , minced 1 red bell pepper , 1/4-inch dice 1 green bell pepper , 1/4 inch dice 5 large mushrooms , 1/4-inch dice 2 tablespoons unsalted butter[...]