Ask your butcher for the heart sweetbreads, which are plumper and less sinewy.
250g plump lamb sweetbreads
A little olive or rapeseed oil for frying
300-350g asparagus, woody ends removed
2tbsp capers, rinsed
1tbsp chopped parsley
Put the sweetbreads in a pan of cold salted water, bring to the boil, simmer for a minute; drain. Leave to cool; remove any sinewy membranes and cut them into even-sized pieces.
Heat a tablespoon of oil in a pan, season the sweetbreads; fry them on a medium heat for 4-5 minutes, turning them as they are cooking until they begin to crisp.
While the sweetbreads are cooking, put the asparagus in boiling salted water for 3-4 minutes until just cooked; drain. Add the butter to the pan with the sweetbreads until it begins to colour; remove from the heat; stir in the capers and parsley.
To serve, arrange the asparagus on warmed serving plates and spoon the sweetbreads, capers and butter on top.