For the BBQ sauce with deep fried chicken wings, heat the oil for deep-frying to 180C/350F (use a cooking thermometer) in a deep-sided pan not more than half full, or alternatively use a deep fat fryer. (CAUTION: hot oil can be dangerous. Do not leave unattended.)
Season the chicken with salt and pepper and place in the deep fat fryer. Cook for 6-8 minutes or until golden-brown and crisp. When cooked, remove with a slotted spoon and leave to drain on kitchen paper. Season to taste with more salt.
Fry the onion and garlic in olive oil with the chilli, fennel seeds and sugar for 2-3 minutes. Add the soy sauce and ketchup and season with salt and pepper.
Bring to the boil and simmer for a few minutes to combine the flavours.
For the chilli sauce with griddled fillet steak, heat a large frying pan and, when hot, add the vinegar, sugar and soy sauce and bring to the boil.
Add two of the red chillies, the chipotle chilli and ginger. Cook for 2-3 minutes, or until the mixture is thickened and sticky.
Heat the oil in a griddle pan. Rub the steaks with oil and salt and pepper. Place on the hot griddle pan and cook each side for a couple of minutes (depending on how rare you like your steaks).
Serve the chicken wings in a bowl with the sauce over the top and sprinkle with half the flatleaf parsley.
To serve the steak, slice the steak, spoon the sauce over and garnish with chopped parsley and the remaining red chilli.
The barbecue sauce can be used as a dip or to coat spare ribs, chicken or sausages.