Preheat the oven to 220C, fan-forced. Line an oven tray with baking paper. Cut the unpeeled pumpkin into 2cm chunks. Combine the sumac and 2 tsp olive oil in a large bowl. Add the pumpkin, season with salt and pepper and toss to coat. Put the pumpkin on the lined tray and bake for 20-22 mins until golden and tender.
Step 2 — Pickle carrot
Meanwhile, peel the carrot into ribbons with a vegetable peeler. Put 1 tsp sugar and 2 tsp white vinegar in a bowl and stir until the sugar dissolves. Add the carrot and toss to combine. Set aside to pickle, tossing occasionally, until needed.
Step 3 — Cook patties
Heat 1 tbs olive oil in a medium frypan over medium-high heat. Season the plant-based patties with salt, then add to the pan and cook for 4-5 mins each side until golden and heated through. Add the sweet chilli sauce (see cooking tip) and sesame seeds to the patties. Cook, turning halfway, for 1 min or until glazed. Remove the pan from the heat.
Step 4 — Toast rolls
While the patties are cooking, halve the rolls through the middle. Put on an oven tray, cut-side up, and bake for 5 mins or until lightly toasted.
Step 5 — Toss salad
Combine 2 tsp white vinegar and 2 tsp extra virgin olive oil in a large bowl and season with salt and pepper. Add the salad leaves and toss to coat.
Step 6 — Get ready to serve
Drain the carrot, discarding the pickling liquid. Spread the roll bases with the vegan mayonnaise. Divide the patties and pickled carrot among the bases and drizzle with the pan juices. Sandwich with the roll tops and serve with the pumpkin gems and salad.