Preheat the oven to 220C, fan-forced. Line an oven tray with baking paper. Cut the unpeeled sweet potato into wedges. Thinly slice the onion. Peel the cucumber into ribbons with a vegetable peeler. Put the cucumber and a pinch of salt in a bowl and toss to coat.
Step 2 — Roast sweet potato
Put the sweet potato on the lined tray. Scatter over half the curry powder* (see Make it yours), drizzle with 2 tsp olive oil, season with salt and pepper and toss to coat. Roast, turning halfway, for 20-25 mins until tender and golden.
Step 3 — Caramelise onion
While the sweet potato is cooking, heat 2 tsp olive oil in a medium frypan over medium heat. Cook the onion, stirring, for 4 mins or until softened. Add 2 tsp balsamic vinegar, 2 tsp sugar and 60ml (¼ cup) water, season with salt and pepper and cook, stirring occasionally, for 5 mins or until the onion is caramelised. Remove from the pan and reserve the pan.
Step 4 — Cook patties
Scatter the barbecue seasoning over both sides of the plant-based patties, pressing to coat. Heat 2 tsp olive oil in the reserved pan over medium-high heat. Cook the patties for 4-5 mins each side until browned. Remove the pan from the heat.
Step 5 — Serve up
Meanwhile, cut the buns in half. Put on an oven tray, cut-side up, and bake for 5 mins or until toasted and golden. Spread the bun bases and tops with the mayonnaise and tomato sauce, if using. Layer the bases with the patties, cucumber ribbons and caramelised onion. Sandwich with the bun tops and serve with the sweet potato wedges. Enjoy!
Step 6 — Make it yours
Our curry powder is mild, but if you have little ones who aren't keen on too much spice, use less or don't sprinkle it over their portion of the wedges.