Preheat the oven to 220C, fan-forced. Line an oven tray with baking paper. Cut the carrots and unpeeled sweet potato into 2cm chunks. Thinly slice the onions.
Step 2 — Roast vegetables
Put the carrot and sweet potato on the lined tray. Drizzle with 2 tsp olive oil, season with salt and pepper and toss to coat. Roast for 25 mins or until golden and tender.
Step 3 — Cook onion
While the vegetables are roasting, heat 1 tbs olive oil in a small saucepan over medium heat. Add the onion, season with salt and pepper and cook, stirring occasionally, for 6-8 mins until soft and golden.
Step 4 — Cook beef patties
WAGYU BEEF PATTIES OPTION Meanwhile, heat 1 tsp olive oil in a medium frypan over medium-high heat. Add the beef patties to the pan, season with salt and pepper, then cover and cook for 4 mins each side or until cooked through.
Step 5 — Toast bread rolls
Halve the bread rolls through the middle. Put the rolls on an oven tray, cut-side up, and bake for 5 mins or until lightly toasted.
Step 6 — Get ready to serve
Add 2 tsp balsamic vinegar and 1 tsp honey to the onion and cook for 1-2 mins until caramelised and slightly thickened. Thinly slice the tomato. Divide the bread rolls among plates. Spread the bread rolls with the burger sauce, then fill with the spinach, tomato, patties and caramelised onion. Serve with the roast vegetables.