In a medium bowl whisk together the garlic, orange juice, soy sauce, red chili sauce, red chili flake, smoked paprika, onion powder, brown sugar and porter.
Sprinkle the chicken thighs on all sides with salt and pepper.
Add chicken to the marinade, cover and chill for at least 2 hours and up to 8 hours.
Preheat oven to 400.
Pour the chicken and the marinade into a cast iron skillet.
Bake at 400 for 15 minutes. Turn chicken over and continue to bake until cooked through, about 15 additional minutes.
Remove chicken from the skillet and transfer to a serving platter.
Place the skillet and the marinade over high heat, stirring occasionally, until reduced and thickened. Pour glaze over chicken before serving.
Note: if you don’t own a cast iron skillet, pour the chicken and marinade into a baking dish. Once the chicken is cooked through, pour marinade into a pot and cook until reduced to a glaze.
Note: If glaze becomes too thick and sticky, return to heat, stirring in a few splashes of beer to thin.