Preheat the oven to 200°C/400°F/gas 6. Scrub 2 sweet potatoes and chop into 2.5cm cubes. Peel 300g of butternut squash or pumpkin and 2 carrots, then cut into wedges. Toss in a large roasting tray with 150g of sweetcorn. Bash up 1 tablespoons of coriander seeds in a pestle and mortar with ½ a tablespoon of dried oregano and a good pinch of sea salt and black pepper, then sprinkle over the veg. Drizzle with 1 tablespoon of olive oil, give everything a good toss, then roast for 35 minutes, or until golden and soft, shaking the tray halfway through. Meanwhile, peel and finely chop 2 onions and 2 cloves of garlic, then finely chop 1 fresh red chilli. Deseed 1 green pepper and finely chop, along with 2 sticks of celery. Drizzle 2 tablespoons of olive oil into a large pan over a medium-low heat. Add the garlic, onion, chilli, pepper and celery, and cook for 10 minutes, or until softened but not coloured. Tip 2 x 400g tins of black beans into the pan (juices and all), then scrunch in 1 x 400g tin of plum tomatoes through clean hands. Season and bring to the boil, then reduce the heat to low and leave to tick away for 30 minutes, or until thickened. For the salsa, pick and chop the leaves from 1 bunch of fresh mint (30g), then trim and chop 8 spring onions. Place in a bowl, halve 4 limes and squeeze over the juice, then add a few splashes of chipotle Tabasco and stir together. Cook 300g of brown rice according to the packet instructions, then drain and set aside. When the veg is starting to turn golden, remove from the oven. Push the contents to the sides of the tray, leaving a space in the middle. Ladle the beans into the tray and return to the oven for a further 20 minutes, or until sticky and golden. Stir the roasted veggies into the beans and serve with the rice and salsa on the side.