Mexican chicken burgers

Method

1. Put the chicken breasts between 2 sheets of baking paper and use a meat tenderiser or rolling pin to flatten them to a 2-3cm thickness. Put the chicken in a non-metallic bowl with the oil, cumin, juice of 2 limes, the sliced garlic clove and half the chipotle paste. Marinate for at least 30 minutes, but preferably overnight, in the fridge.
2. Put the onion rings in a bowl of water (to reduce the sharpness). In another bowl, mash the avocados with the crushed garlic, the rest of the lime juice and chipotle paste, the chilli and half the coriander.
3. When the chicken has marinated, heat a large griddle pan. Once the pan is smoking hot, add the chicken and griddle for 5-6 minutes on each side, basting with the marinade. The chicken should be lightly charred and cooked through – cut into the thickest part to check.
4. To serve, layer the grilled rolls with the mashed avocado, onion rings and chicken, sprinkle with the remaining coriander and serve with soured cream, lime wedges and curly fries (if you like).