Preheat the oven to 350°F (175°C). Lightly grease a 9×5-inch loaf pan or a baking sheet with oil, or line with parchment paper.
In a skillet, heat 1 tablespoon of olive oil over medium heat. Add chopped onion, minced garlic and sauté until soft and translucent, about 3-5 minutes.
In a large mixing bowl, combine ground turkey with sautéed onion and garlic, egg, ketchup, oats (or panko), Greek yogurt, Worcestershire sauce, salt, and pepper. Mix until just combined.
Transfer the mixture into the prepared loaf pan, pressing it down gently. Spread a thin layer of extra ketchup on top for glazing.
Bake on the middle rack of your hot oven for 40-45 minutes, or until the inside is cooked through and the top is lightly browned.
Let cool for at least 5 minutes before slicing and serving.