Step 1 Preheat oven to 180°C. Place pumpkin, capsicum and red onion onto a large baking tray. Drizzle with oil and vinegar. Toss to coat. Bake for 35 minutes, or until golden and tender.
Step 2 Meanwhile, combine mince, breadcrumbs, brown onion, garlic, relish and sauce in a large bowl. Using damp hands, mix to combine. Using 1/4 cup mixture at a time, roll into 12 balls then flatten slightly.
Step 3 Place a large frying pan over medium heat. Spray patties with oil. Cook, turning occasionally, for 12–15 minutes, or until cooked through.
Step 4 Meanwhile, place baby spinach and roasted vegies into a large bowl. Toss gently to combine. Serve patties with pumpkin and spinach salad.