1. Heat a small amount of cooking oil in a frying pan. Brown portobello mushrooms, season with salt and pepper then remove from pan and set aside.
2. In the same pan, sauté onion and garlic until softened. Deglaze with soy sauce then remove from pan.
3. In a food processor, add mushrooms, sauteed onion and garlic, beetroot, tempeh, rice, oats and barbeque sauce and process until the mix resembles mince.
4. Form the mixture into 5 burger patties and fry each side for 2-3 mins.
5. To make the vegan aioli, combine the soy milk, garlic, mustard and vinegar in a blender and blitz until well combined. While continuing to blend, slowly drizzle in the oil until thickened to an aioli consistency.
6. To assemble, lightly toast the burger buns and spread 1 tablespoon tomato chutney on the bottom of each bun, top with the burger patties, 2 lettuce leaves, 2 tomato slices, 2 pickles slices and 2 red onion slices. Spread a tablespoon of vegan aioli on top of each burger bun and place on top.