Chop the peppers small and add all the rub ingredients, except the chili infused oil, to a small food processor. Drizzle in and blend until a smooth paste.
Pat chicken dry.
Use your fingers to lift the skin from the breast, put some of the rub on the meat and on the skin.
Put rub on entire outside of the chicken with the rub.
Give entire chicken a light dusting of the ground jalapeno powder and sea salt.
Slice the leeks and onion into 1 1/2" thick slices and layer in the bottom of a roaster (or if spatchcocked, a cookie sheet), sprinkle with salt and pepper and the all purpose rub.
Place the chicken on top and bake at 350°F for 20-25 minutes per pound until cooked through.
Remove the chicken, leeks, and onions and use the drippings for your gravy base.