Ultimate vegetable chilli

Name: Ultimate vegetable chilli
Prep time: 20 min
Cook time: 1 h 30 min
Total time: 1 h 50 min
Cuisine: British, Mexican
Ingredients: 6 - 12 dried chillies (I use a mixture of casabel, ancho, chipotle and guajillo but see notes); 3 tbsp oil; 2 onions, finely chopped; 3 cloves of garlic, finely chopped; 1 tsp cumin; 2 tbsp tomato puree; 800 g tinned chopped tomatoes (2 tins); 1 small bunch beetroot, peeled and chopped into 2 cm pieces; 1 butternut squash, or any other squash, chopped into 2 cm pieces (about 800 g in total ); 1 tin black beans, drained (approximately 240 g of cooked beans if not using them from a can); chopped coriander, to serve; 1 avocado, sliced to serve; 1 lime, sliced to serve; sour cream, to serve; cheddar cheese, to serve