Slice the tomatoes: Slice off the stem of the tomatoes. Place them on their side and slice crosswise to get thin round slices.

Prepare the lettuce: Wash the leaves carefully, then dry them with a salad spinner.

Slice the red onions: Slice the onion in half, then remove the root and head. Peel off the skin, then slice the onion halves thinly.

Chop the parsley: Bunch the parsley together and chop finely.

Make the sauce: Prepare a small bowl. Add 3 tbsp Buffalo sauce, 2 fl oz water, 1 tbsp white vinegar, 1 tbsp honey, 1/2 tbsp Heinz ketchup, 1/2 tsp paprika, 1/2 tsp garlic powder, 1/2 tsp chili powder, 1/2 tsp ground black pepper, 1/4 tsp salt, and 1 tsp all-purpose flour. Mix until combined.

Sear the chicken: Put a pan over medium heat until hot. Add 1/2 tbsp olive oil and 16 oz chicken thighs. Sear the chicken on both sides for 7 minutes in total. Remove the chicken from the pan.

Cook the sauce: Add the sauce to the same pan. Stir in 1/2 tbsp unsalted butter for 2 minutes on low heat.

Finish the chicken: Add the chicken back to the pan. Cook in the sauce for 3 minutes.

Prepare the buns: Cut 4 burger buns in half crosswise.

Toast the buns: Add the cut buns to an air-fryer. Cook in the air-fryer for 4 minutes at 390 °F.

Build the sandwich: Place the bottom halves of the buns at the bottom and spread 3 tbsp plain Greek yogurt on them. Continue building the sandwiches with 4 oz green lettuce, 6 oz tomatoes, 1 oz red onion, and the chicken (one piece of chicken per sandwich).

Garnish and serve: Sprinkle 2 tbsp parsley on top of the chicken before placing the other half of the buns on top. Enjooy.