Soak the sweetbreads in cold salted water for at least 30 minutes.
Change the water, salt it and bring them to the boil.
Cook for 10 minutes.
Strain and let them get cold, then remove any skin or membrane.
Take the rind from the rashers and wrap each sweetbread in the bacon.
(If the sweetbreads are not all the same size, cut them accordingly.) Put into a lightly greased, oven-proof dish, season well, add the small onion finely chopped, the sliced peeled tomatoes and stock.
Sprinkle with the parsley and cook in a moderate oven (350Â° F. electric; gas regulo 3-4) for 35-40 minutes.
If any of the bacon is not utilized, roll into curls and grill them.
Use these crisp bacon rolls as a garnish on top of the sweetbreads when serving.