Season pork with salt and pepper. Add the olive oil to a large deep oven proof pot or Dutch oven and brown pork on all sides. Remove pork and place on a plate. Add onions and sauté until soft. Add garlic and sauté for a minute. Add beer, deglaze pan and reduce beer by half. Add beans, BBQ sauce, brown sugar and stir until evenly combined. Add pork to pot, cover and bake in a preheated oven at 375 degrees for about 1 hour or until pork is done. Cooking times will vary depending on the thickness of the pork. No pink should remain in the middle. Let rest for at least 15 minutes or longer for flavors to blend, meat to rest and sauce to thicken. Remove pork and cut on a diagonal. Serve over beans or another option is to transfer the contents of the pot to a crock pot and cook over low heat for about 4-6 hours instead of cooking it in the oven. This way dinner can be done when you arrive home!