Place the pepper halves in a roasting pan or pie plate, cut side facing up. Fill the pepper halves with sausage. Place a feta slice on top of the sausage, followed by the tomato halves. Drizzle with the olive oil and sprinkle sparingly with salt.
Roast for 1 hour and 10 minutes, or until the peppers are soft and beginning to brown on the edges. Serve warm.