One day before grilling, prepare the vegetables to pickle by cutting them into fine strips.
Bring mustard seeds, sesame seeds, sesame oil, salt, mirin, rice wine vinegar, sugar and Ponzu soy sauce to the boil in a saucepan and add approx. 250 ml water.
Simmer for 2-3 minutes.
Put the vegetables in an airtight glass, pour in the vinegar water and close the lid. Leave in the fridge overnight.
For the chicken marinade melt butter, sauté garlic in it and add the remaining ingredients. Bring to the boil briefly and allow to cool slightly.
Put the chicken in a bowl and marinate for at least 2 hours.
Core the cucumber, halve lengthwise and cut into fine strips. Mix with skyr, season to taste with salt and pepper.
Now it gets serious and the chicken is ready to grill. Remove the chicken from the bowl and keep the rest of the marinade and set aside.
At medium heat grill covered for 10-15 minutes.
Then brush on both sides with the marinade set aside and grill for another 10 minutes covered.
Briefly heat the tortillas on the grill.
First cover with cucumber skyr and pickled vegetables.
Cut the chicken into strips and place them on top of the tortillas. Garnish with spring onion and sesame seeds and then either eat them like a taco or simply roll into a wrap.