2 pieces beef tenderloin
1 tbsp Vegetable oil
3 tsp unsalted butter
⅓ cup sweet onion
1 clove garlic
½ tsp salt
¼ cup sherry or red wine
1-2 sprigs thyme
4 pieces prosciutto
2 sheets puff pastry
1 tbsp honey mustard or dijon
1 tbsp water
Salt and pepper the meat thoroughly.
Heat pan w/ vegetable oil until very hot (almost smoking), add 3 tbsp butter to oil and mix. Sear all sides of the meat, (about 1-2 minutes per side) or until browned. Put the meat on a plate and place it in the freezer to cool it quickly.
Cool the pan and begin chopping the onion, mushroom and garlic. You want the pieces finely chopped.
Cook the onion, mushroom and garlic on medium heat with oil and fat in pan. Cook for about 10-15 minutes, stirring occasionally until mushrooms are browned and onion translucent.
After mixture is cooked, add a ¼ cup of sherry or red wine and a sprig of thyme. Cook for about 5 minutes, until reduced. Remove mixture from heat and place in a bowl to cool.
Preheat oven and get out puff pastry if frozen. Make sure that butter does not melt and remains relatively cold.
Take a piece of puff pastry and unfold. Make sure to wait until your puff pastry is easily bendable without cracking. Place the prosciutto on the pastry, followed by mushroom mixture. Brush one side of the beef with mustard, then place on mixture, followed by mustard on top, mushroom and prosciutto. Take one corner at a time and fold over the top of the beef, trying to create a tight seal. If you have excess dough, you can cut or pinch it off. Take your time to push the pastry to be a rounded ball and fully seal the meat.
Whisk 1 egg and mix 1 tbsp of water to create an egg wash. Brush on the egg wash on all sides.
Put the wellingtons in a glass baking dish lined with parchment paper. Bake in the oven for about 25 minutes or until center reaches a temperature of 135-140F. Let sit for 10 minutes at least.