Burnt End Tacos with Pickled Red Onion

Ingredients

• 500g leftover brisket burnt ends, cut into rough 2cm cubes
• 2 tbsp leftover brisket juices or beef stock
• 1 tbsp dark brown sugar
• 1 tsp smoked paprika
• 1 tsp cider vinegar
• black pepper
• 1 large red onion, halved and finely sliced
• 100ml cider vinegar
• 100ml just-boiled water
• 1 tbsp caster sugar
• 1 tsp fine salt
• 1 tsp black peppercorns
• 200g sweetcorn (tinned and drained, or cut from 2 cobs)
• 1 tbsp neutral oil
• 1 jalapeño, finely diced (deseed if you want less heat)
• 1 small avocado, diced
• juice of 1 lime
• small handful coriander, roughly chopped
• pinch of salt
• 150g tomatillos (tinned is fine), or 200g green tomatoes
• 1 garlic clove
• 1 green chilli
• small handful coriander
• juice of ½ lime
• ½ tsp salt
• ½ tsp ground cumin
• 8 small corn tortillas
• 80g cotija or feta, crumbled
• extra coriander leaves, to scatter
• 1 lime, cut into wedges

Method

1. Start the pickled onions first — they need 20 minutes minimum to soften and turn. Pack the sliced onion into a jar with the peppercorns. Whisk the cider vinegar, just-boiled water, sugar and salt until fully dissolved, then pour over the onion and press it under the liquid. They're ready when the colour shifts from harsh purple to bright magenta and the raw bite is gone.
2. Make the salsa verde. Blitz the tomatillos, garlic, green chilli, coriander, lime juice, salt and ground cumin in a small blender until mostly smooth with a little texture. The cumin needs to bloom — warm 1 tsp of oil in a small pan, tip in the cumin for 30 seconds until fragrant, then scrape it into the blender before the final pulse. Raw cumin tastes dusty; bloomed cumin tastes of itself. Taste and season — it should land sharp, savoury, and lightly hot. Loosen with a splash of water if it's too tight.
3. Char the sweetcorn. Set a stainless or cast iron frying pan over high heat with the oil until it shimmers, then add the corn in a single layer — don't crowd it or it steams instead of charring. Leave it alone for 2–3 minutes. You want black blistered spots on the kernels; that char is where sweetness turns deeper and smokier. Toss once, char another minute, then tip into a bowl with a pinch of salt and let it cool for a moment. Fold in the jalapeño, avocado, lime juice and coriander — wait until the corn has cooled or the avocado turns to mush.
4. Reheat the burnt ends low and slow. Tip them into a small heavy pan with the brisket juices or stock, brown sugar, smoked paprika, cider vinegar and a heavy crack of black pepper. Cover and warm over the lowest heat for 5–6 minutes, stirring once or twice. High heat will dry the bark out and undo the whole point of the original 12-hour cook. They're ready when the cubes are glossy, sticky, and hot through. Taste the glaze — adjust the salt and pepper now, not at the table.
5. Char the tortillas one at a time directly over a gas flame for about 10 seconds a side, using tongs, until you see black freckles and they puff slightly. No gas hob? A dry pan on the highest heat for 30 seconds a side does the same job. The char isn't optional — raw corn tortillas taste of cardboard, charred ones taste of Mexico. Stack them under a clean tea towel as you go so they stay warm and pliable.
6. Build at the table. Lay two charred tortillas flat per plate, pile on the sticky burnt ends, spoon over the charred corn salsa, drape a tangle of magenta pickled onions across the top, then drizzle with the salsa verde. Crumble the cotija generously, scatter the extra coriander leaves, set a lime wedge alongside for a final squeeze of lime over the lot, and put the hot sauce and pickled jalapeños on the table within reach.