DIRECTIONS

1. In a small bowl, whisk together the mustard, sour cream, mayonnaise and salt and pepper until well blended. Cover and refrigerate.
2. In a medium bowl, mix the mushrooms, garlic, shallots, and thyme; set aside.
3. Cut larger tip pieces in half so you end up with 18 portions of beef.
4. Dry the beef and season with salt and pepper.
5. In a hot pan on high heat, add the avocado oil and heat until shimmery.
6. Add the tips and move them around constantly for about 30 seconds – do not over cook.
7. Immediately transfer the tips to a shallow dish or plate and refrigerate.
8. In the same skillet, add the butter and melt on medium heat.
9. Add the mushroom mixture and sherry and cook until the mushrooms have released most of their liquid (about 8 minutes).
10. Remove from heat and drain the mixture on a paper towel. Allow to dry and cool.
11. Preheat oven to 400° F and line a baking sheet with parchment paper; set aside.
12. On a floured surface, unfold the thawed puff pastry and cut each sheet into 9 squares.
13. Cut the prosciutto into 18 pieces.
14. Once beef and mushrooms are cooled, place a piece of prosciutto onto each square.
15. Top the prosciutto with about 1 Tbsp. of mushroom mixture then top each with a portion of beef.
16. Fold up two opposite corners of the puff pastry to the center of the square.
17. Repeat with the remaining two corners and gently press the four together.
18. Repeat with all the puff pastry pieces.
19. Place the filled pastries, seam side up, on the prepared baking sheet and brush with a beaten egg.
20. Bake for 15-20 minutes or until the puff pastry is puffed and golden.
21. Serve with Dijon sauce topped with chives.
22.