Pat the short ribs dry with paper towel, then season generously on all sides with salt and cracked pepper.

Heat a heavy pot or large Dutch oven over medium high heat. Add the neutral oil. Sear the ribs until deeply browned on all sides (work in batches if needed so the pot isn’t crowded). Transfer ribs to a plate. Carefully pour off excess fat, leaving about 2 tbsp in the pot.

Add the thinly sliced onions and a pinch of salt. Reduce to medium heat, then low heat as needed and cook, stirring occasionally, until the onions are soft, dark, and jammy — about 15 minutes.

Add the smashed garlic, tomato paste, and maple syrup. Cook, stirring, for 5 minutes to caramelize the paste and mellow the garlic.

Pour in the Guinness and scrape up all the browned bits from the bottom of the pan. Let it simmer for 2–3 minutes to smooth out any bitterness.

Add enough beef stock to come about halfway up the ribs once they’re returned to the pot. Stir in the thyme and bay leaf.

Return the ribs (and any juices) to the pot, arranging them so they’re nestled into the liquid. The liquid should come halfway up the meat. Cover with a lid.

Transfer to a 300°F (150°C) oven and braise for about 3 hours, or until the ribs are deeply tender.

Carefully transfer the ribs to a serving dish and cover loosely to keep warm.

Skim excess fat from the surface with a ladle. Set the pot over high heat, bring to a boil, then reduce for 5–10 minutes to concentrate the flavour.

In a small glass, whisk together ¼ cup corn starch and ¼ cup water until smooth. While the sauce is boiling, slowly pour in the slurry, stirring constantly. The sauce will thicken in 2–3 minutes.

Reduce heat to low and stir in ¼ cup butter until glossy. Taste and adjust salt as needed.

Spoon the sauce over the ribs and finish with green onions (and optional chopped parsley or chives).