Clean the fat from the fillet, cut the fillets, add salt and pepper and mark in the frying pan.
Peel the onion and to cut it into julienne strips, poach it on a low heat in the same frying pan where we’ve made the fillet to use the juices and to highlight the flavour.
Half-way through the poaching, add the sugar and caramelise.
Slightly heat the bread to spread the sobrassada more easily.
Then add the pieces of meat and finish with the caramelised onion.