Heat the extra virgin olive oil in a wide pot over medium heat. Once hot, add the diced onion and cook, stirring occasionally, for 5-6 minutes until it begins to soften.
Add the capers and anchovies and cook for 3-5 minutes, stirring regularly, until the capers begin to turn golden brown. Using your spoon, mash the anchovies into the man until they 'melt'. Drizzle in 1-2 teaspoons of the anchovy oil from the can and season everything with a few generous shakes of crushed red pepper. Season lightly with salt and pepper to taste.
Add the garlic to the pan and cook for 1 minute or until it's fragrant. Do not burn the garlic.
Melt the butter into the pan and cook for 2-3 minutes until it is bubbly and beginning to brown slightly.
Deglaze the pan with the white wine and bring to a boil for 3-4 minutes until it reduces slightly. Turn heat to low.