Vegetable oil (or other high flashpoint oil), for frying
Heat a saucepan over medium heat. Melt the butter, and then stir in the garlic. Cook for 1 to 2 minutes, or until the garlic is lightly browned.
Add hoisin, tomato sauce, soy sauce and chile-garlic sauce. Reduce heat to low and simmer the sauce for about 3 to 5 minutes or until thickened. Set aside.
Rinse the chicken wings and pat them dry. Generously season the chicken with salt and black pepper. Dredge the wings in flour, shaking off any excess flour, and set aside.
In a large saucepan or deep fryer, heat the oil to about 375°. Fry the chicken wings in small batches until golden brown, 8 to 10 minutes. Shake off any excess oil and place on paper towels to drain. Continue frying the chicken in batches until all of the wings are cooked.
Toss the wings in the hoisin sauce and serve warm.