Preheat the oven to 220C, fan-forced. Line an oven tray with baking paper. Cut the unpeeled sweet potato into 1cm-thick chips. Thinly slice the cabbage with a sharp knife or mandoline. Thinly slice the jalapeno (see Make it milder). Crush or finely chop the garlic.
Step 2 — Roast chips
Put the sweet potato on the lined tray. Drizzle with 2 tsp olive oil, season with salt and pepper and toss to coat. Roast on the upper oven shelf for 25 mins or until golden and tender. Meanwhile, combine 2 tsp white vinegar, ½ tsp sugar and a pinch of salt in a bowl. Add the jalapeno and toss to combine. Set aside to pickle, tossing occasionally, until needed.
Step 3 — Pan-fry patties
Put the beef mince, garlic and barbecue seasoning in a large bowl and season with salt and pepper. Using damp hands, combine well, then shape into 2 equal patties. Heat 2 tsp olive oil in a medium frypan over medium-high heat. Cook the patties for 3-4 mins each side until cooked through. Remove from the pan.
Step 4 — Toast rolls and make slaw
Meanwhile, cut the rolls in half. Put on an oven tray, cut-side up, and bake on the lower shelf for 3-4 mins until lightly toasted. Put the cabbage and 2 tbs mayonnaise in a bowl, season with salt and pepper and toss to coat.
Step 5 — Serve up
Layer the roll bases with the slaw, patties and drained pickled jalapeno. Sandwich with the tops and serve with the sweet potato chips. Enjoy!
Step 6 — Make it milder
Not a fan of chilli? No problem – simply discard the seeds from the jalapeno to reduce the level of heat. Or, serve the pickles at the table for those who like things spicy.