Preheat oven to 400°F (200°C).
In a baking dish, combine cherry tomatoes and red onion. Drizzle generously with olive oil. Season with garlic powder, dried oregano, salt, and pepper. Add half of the fresh oregano leaves and toss gently to coat.
Nestle slices or crumbles of goat cheese into the tomato mixture. Drizzle lightly with more olive oil and sprinkle with a pinch of dried oregano.
Bake for 40 minutes, or until tomatoes are bursting, onions are soft, and goat cheese is golden around the edges.
Cool for a few minutes, then garnish with remaining fresh oregano.
Serve warm with crusty bread, toss with pasta, or spoon over grilled protein.