Blitz together the garlic, onion, lime juice, fish or Worcestershire sauce, chilli, sugar, soy and coriander. Add to the turkey and marinade for a few nights or overnight.
Cook the breasts under a hot preheated grill or an a griddle pan on high heat for 6-8 minutes, turning occasionally until properly cooked through.
To make the sauce, tip the peanut butter into a heatproof bowl and add the soy sauce. Gently whisk in the hot water. Continue until it reaches “dipping” consistency (like half whipped cream).