Place 1 tbsp chia seeds and 3 tbsp of water in a mixing bowl and mix well. Let sit for 5 mins and mix a few more times
Chop beetroot to 4-5 pieces and put them in a food processor, process well
Add chickpeas and process until everything is mixed well but still has a bit of chunks
Put the mixture as well as the other ingredients and the chia seed mixture into a big bowl and mix with your hands
Divide the mixture into 8-10 pieces and shape into patties, if mixture is to wet, add more potato starch
Heat a frying pan with oil and fry patties for 3-5 mins on each side until lightly browned
For the sauce
Put all the ingredients in a mixing bowl and whisk until sauce reaches smooth consistency. If the sauce is to thick, add some water or more orange juice until it reaches desired consistency
Assembly for burger
Lightly toast brioche buns
On bottom bun, spread tzatziki or lemon garlic tahini sauce
Place beetroot patties, top with arugula, pickles and more garlic tahini sauce and cover with top bun
Serve immediately
Assembly for a salad
On a plate, add arugula, thinly sliced radishes and black olives
Drizzle olive oil and salt & pepper to taste
Place patties on top of salad
Drizzle with lemon garlic tahini sauce