Pork Wellingtons with apple brandy beurre blanc Recipe

Ingredients

• 1 cup peeled and diced Granny Smith apples
• 1 cup chopped onions
• 1 Tbsp. chopped thyme
• 2 Tbsp. each unsalted butter and apple brandy
• 1 Tbsp. brown sugar
• ½ tsp. kosher salt
• 1 Tbsp. olive oil
• 1 pork tenderloin (1 lb.), trimmed and seasoned with salt and black pepper
• 1 sheet frozen puff pastry, thawed (half a 17.3-oz. box)
• 4 tsp. whole-grain mustard
• 8 slices prosciutto
• 1 egg + 1 Tbsp. water, beaten
• ⅓ cup apple brandy
• ⅓ cup. cider vinegar
• 2 Tbsp. minced shallots
• 1 ½ sticks cold, unsalted butter (12 Tbsp.), cut into tablespoons
• 2 tsp. whole-grain mustard
• Salt and black pepper to taste