Add all of the tartar sauce ingredients to a bowl and mix well. Cover and refrigerate.

Add the tilapia to a food processor along with lemon zest, salt and pepper. Pulse to chop into small pieces. Take ¾ of the chopped tilapia and transfer to a bowl. Add the Dijon mustard to the food processor and pulse to make a paste (this will be the binder to hold them together). Remove and add to the bowl with the rest of the tilapia. Add the chives and dill, mix well.

Divide the mix into 4 equal parts. Take ¼ and firmly form into a ball, then shape into a burger patty, 1-inch (2 cm) thick.. You can prepare them up to 2 days ahead, cover and refrigerate.

Repeat with the rest of the tilapia and refrigerate for 30 minutes (this will prevent them breaking apart when cooking).

Preheat a cast iron skillet, or non-stick heavy pan over medium-high heat and add the oil. When the oil starts to ripple carefully place the burgers in the pan, you can work in batches if they don’t all fit. Cook for 4-5 minutes, do not move. When they are browned and lift easily from the pan, they are ready to turn. If you turn too soon, they will fall apart.

Cook 3-4 minutes on the other side. Remove.

To bake: Place the burgers on a parchment paper lined baking sheet/tray and bake 425°F/220°C for 30 minutes, flipping halfway through.

Serve with the tartar sauce and coleslaw on a bun.