Heat the butter in a frying pan, add the onion, garlic, smoked paprika and thyme. Cook for 1-2 minutes until the onions are softened but not coloured. Place in a bowl to cool.
Add the chilled meat, barbecue sauce, parsley and egg yolks, and season to taste. Carefully bring the mix together, making sure not to overwork it or it will become tough. Chill in the re