Add half the oil in your Roasting pan rinse roast add to pan.

Use a knife and poke holes in roast almost to bottom

Peel garlic cloves cut in half, cut jalapeño long ways . In half then in half again stuff in holes in roast. In each hole put garlic and jalapeño

After stuffing rub remaining oil then generously sprinkle with seasoning add your water to pan sprinkle some more seasoning in water add vinegar as well

Cover with foil bake on 350 for about 2 to 3 hours

After an hour check roast you can wisk in the corn startch at this point if you want to thicken the gravy.

Slice and serve with your favorite sides.