Preheat oven to 425°F.
Heat a medium-size skillet over medium-high heat with 2 turns of the pan of EVOO, about 2 tablespoons. Once hot, add the onions and garlic, and cook until soft, about 6-7 minutes. Remove the pan from heat, spoon contents into a medium-size mixing bowl and let cool. Once the onions and garlic are cool enough to handle, add the chicken to the bowl with the sun-dried tomatoes, basil, oregano, fennel, chili flakes, cheese, salt and freshly ground black pepper. Mix to combine.