Heat a frying pan until hot, add a splash of the olive oil and all the onions; fry until just softened and coloured. Add the garlic, peppers, tomato and paprika and continue to cook until soft. Tip everything from the pan onto a chopping board, leave to cool slightly and roughly chop to make a coarse pulp.
Heat a separate frying pan until hot, add some more of the olive oil and the chicken thighs and fry until golden-brown. Add the squid and Serrano ham and fry for a couple of minutes.
Add the sherry vinegar and deglaze the pan, then tip the pepper mix back into the pan, along with the chopped parsley. Stir well and simmer until the chicken is cooked through .
Season with salt and freshly ground black pepper, to taste. To serve, brush a little squid ink across the plate, then pile the chicken mixture on top.