Spread the gnocchi, tomatoes, bell pepper, zucchini, red onions, and olives on a large rimmed sheet pan. Drizzle with olive oil, then sprinkle on the garlic, oregano, thyme, salt and pepper. Toss directly on the pan until everything is well-coated and then spread in a single layer.
Bake for 25 minutes, stir once, then sprinkle the feta evenly over the top. Return to the oven for 8–10 minutes more, until the tomatoes are blistered and the gnocchi are golden with crisp edges.
Sprinkle the basil over the hot gnocchi and serve right off the pan.