Chop the onion finely.
the tomatoes, remove the seeds and dice them.
In a frying pan, cook the onion on a low
heat until it's transparent, add the tomato and cook a little longer
until you have a sauce.
Pass the onion and tomatoes into a
larger saucepan and when it begins to boil, add the spoonful of flour,
the lentils and the sobresada in one piece.
Cook a bit and then add the stock.
Allow it to cook on a low heat for the
amount of time necessary and stir every now and ten (the sobresada will
fall apart little by little).
Five mintes before it finished cooking,
put the bread with the cheese on top under the grill so that the cheese
Pour the contents into a large tureen
with the toast floating on top or just serve it into individual bowls
with one piece of toast in each bowl.