1. In a large skillet set over medium heat, add 1 tablespoon of the olive oil. Add the onion and garlic and cook until translucent, about 5 minutes. Remove from the heat and set aside to cool.

2. Preheat the oven to 350°. In a large mixing bowl, combine the cooled onion and garlic with the flaked trout, sour cream, mayonnaise, Parmesan, cheddar, lemon zest and juice, chives, salt and white pepper. Mix until well incorporated and transfer to a small oven-safe baking dish. Bake until heated through and the top begins to brown, about 15 minutes.

3. While the dip is baking, place the sliced bread on a rimmed baking sheet and brush with the remaining 1 tablespoon of olive oil. Transfer to the oven and bake until golden, about 10 minutes. Serve the dip warm with the sourdough toast points.