Step 1
To prepare pickled onion, put apple cider vinegar, sugar, salt and one-fourth cup water in a bowl and mix well. Add onion, mix well and set aside for one hour.
Step 2
To prepare Greek yogurt sauce, put Greek yogurt, lemon juice, garlic, parsley, mint leaves and salt in another bowl and mix well. Set aside.
Step 3
Put chicken mince, feta cheese, mint leaves, parsley, red bell pepper, salt and crushed peppercorns in a third bowl and mix well.
Step 4
Divide the chicken mixture into four equal portions and shape them into patties.
Step 5
Break eggs in a shallow bowl and beat well. Spread the refined flour on a plate.
Step 6
Heat sufficient oil in a pan.
Step 7
Coat the chicken patties in the flour, dip in beaten eggs and again coat with the flour. Shake away excess flour.
Step 8
Deep-fry these coated patties in hot oil till golden. Drain on absorbent paper.
Step 9
Halve the burger buns.
Step 10
Put some Greek yogurt sauce on the base half of each burger bun and place some spinach leaves on top. Put a fried patty, top with some pickled onion and cover with remaining buns.
Step 11
Serve immediately.