
Beef Wellington is a favourite celebration dish. If it's made well, it's bound to impress, but it's not easy to get the beef fillet cooked right while maintaining a firm and crisp pastry shell. Plus the fillet of beef is frighteningly expensive. As an experiment, I decided to try making beef wellington with a cheaper cut of beef (I ended up with topside, which cost less than half the price of beef fillet), and pre-cooking it using the sous vide technique. It turned out really well. Some versions of beef wellington have the meat wrapped in Parma ham, and some include a layer of pâté de foie gras. I think the dish is plenty rich enough just with the meat coated in mushroom duxelles, so that's what I'm doing, along with crêpes to stop the bottom going soggy.

700 grams lean beef joint (eg topside)
1 tsp salt
half a tsp black pepper
half a tsp salt
half a tsp thyme
2 tbsp Dijon mustard
250 grams plain (all-purpose) flour
200 grams unsalted butter
about a cup water
pinch of salt
250 grams mushrooms
1 medium onion
1 tsp salt
half a tsp black pepper
half a tsp salt
half a tsp thyme
75 grams plain (all-purpose) flour
125 ml milk
1 egg
pinch of saltEggwash - a beaten egg with a splash of milk.