With the rack in the middle position, preheat the oven to 400°F (200°C).
Place the feta slices in a bowl and cover with cold water. Soak for 10 minutes to remove some of the salt. Drain and pat dry.
Meanwhile, in a bowl, toss the bell pepper and onion with 1 tbsp (15 ml) of the oil.
Place a layer of tomatoes in several ramekins or in a large baking dish. Top with the feta slices, bell pepper and onion. Drizzle with the remaining olive oil and sprinkle with the oregano. Season with pepper.
Bake for 20 minutes or until the vegetables are light golden brown. Top with the olives and serve immediately.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.