Braise the ribs:

In a large stockpot over medium heat, heat the oil. Add the onion, garlic, and jalapeño and cook until the onion is tender, about 5 minutes, stirring occasionally. Add the oregano, cumin seed, salt, and pepper and cook until fragrant, about 30 seconds, stirring constantly. Pour in the lager and add the bay leaf. Place the ribs in the braising liquid, meaty side down, and add just enough water to cover them. Bring to a boil over high heat and then reduce the heat to low. Cover and simmer until the ribs are very tender when pierced with the tip of a knife, about 2-3 hours. (braising time will depend upon size of ribs) Transfer the ribs to a sheet pan to cool. Remove and discard any bones that may have fallen off the ribs in the liquid. Strain the braising liquid through a fine mesh strainer into a large bowl and discard the solids. Cover and refrigerate the cooled ribs and the braising liquid (separately) until chilled, about 2 hours (or overnight if you wish).

Make the sauce:

Skim the fat from the surface of the liquid. Pour the liquid back into the stockpot (now clean) and bring to a boil over high heat. Lower the heat and simmer the liquid until reduced to ¾ cup, 1 to 1½ hours. Transfer to a medium saucepan. Stir in the ketchup, molasses, balsamic vinegar, and Worcestershire sauce. Bring to a simmer over medium heat, then reduce the heat to low, and simmer until the sauce is slightly reduced, about 5 minutes, stirring often. Remove from the heat and season with hot pepper sauce, if desired. Set aside at room temperature.

Finish the ribs:

Remove the ribs from the refrigerator and cut off any large pieces of exterior fat; this will minimize any grill flare-ups. Brush the ribs with the oil and season evenly with the salt and pepper. Preheat the grill to medium and brush the cooking grate clean. Grill the ribs over medium heat until warmed through and the exterior is beginning to turn crispy, turning several times, about 10 minutes.

Brush the ribs generously with the sauce. Turn the heat up and continue to cook until the meat is glazed, about 5 minutes, turning occasionally. Remove from the grill and serve warm with the remaining sauce.