Start by preparing the beetroot mutabbal, add all ingredients to a food processor and blend until smooth. Salt to taste.
Slice the halloumi lengthwise so that you have two slices. Using a round cookie cutter, cut each piece so that you have 2 halloumi burgers.
Brush the halloumi with olive oil (optional) on cook on a griddle pan for 3-4 minutes per side or until lightly golden.
Meanwhile, make the sauce by mixing all ingredients listed under sauce.
Heat the bread in the oven or in a pan for 2 mins.
Assemble the sandwiches by placing the base of the buns on plates followed by the beetroot mutabbal and shredded red cabbage. Top with halloumi, followed by a slice of beetroot and a few avocado slices. Drizzle on the yoghurt sauce then place the top of the bun. Serve immediately.