• 3 garlic cloves
• 1 tbsp. brown sugar
• 1 tbsp. Dijon mustard
• 1 tbsp. olive oil
• 1½ tsp. freshly ground black pepper
• 1½ tsp. ground cumin
• 1½ tsp. paprika
• 1 tsp. cayenne pepper
• 2 tsp. kosher salt, plus more
• 4-5 lbs. untrimmed flat-cut brisket, cut into 4” pieces
• 2 medium onions, thinly sliced
• 1 12 oz. can lager
1. Finely chop garlic in a food processor. Add brown sugar, mustard, oil, black pepper, cumin, paprika, cayenne, and 2 tbsp. salt and process until smooth. Rub all over brisket, working into crevices. Wrap in plastic; chill 1–2 days. Let meat sit out until it’s room temperature, about 1 hour.
2. Scatter onions in a 4–6-quart slow cooker and add brisket, fat side up. Add beer and 1 cup water. Cover and cook until meat is very tender, 7–8 hours on low or 4–5 hours on high.
3. Heat broiler. Transfer brisket, onions, and any braising liquid to a large oven-proof skillet or roasting pan. Broil brisket, uncovered, until top is browned and crisp, 5–10 minutes.
4. Let brisket cool slightly. Remove from pan and shred or slice. Remove onions with a slotted spoon; mix into brisket. Taste and moisten with some cooking liquid and season with salt, if needed.