Place an oven rack in the top position, then turn the oven on to "Broil."
Split English muffins open. Place the english muffins, face up, on a cookie sheet. Brush the open tops of each half with olive oil. Sprinkle oregano or basil on top of the olive oil. Lay tomato slices on English muffin, overlapping the slices slightly. Sprinkle shredded cheese over the tomato slices.
Place the cookie sheet on the top rack of the oven for about 1 - 2 minutes, until the cheese is melted and begins to bubble. Watch the muffins closely because food cooks quickly under the broiler.