Beef En Papillote with Tarragon Butter

How to make it

1. Pat the beef dry and season well with salt, pepper, and a little of the spice mix.
2. Heat the butter in a dutch oven over medium-high and crisp the beef until deeply colored.
3. Add the aromatics with the tomatoes and leeks; cook until fragrant and just tender.
4. Build the tarragon butter sauce in the pan and simmer until it clings to everything.
5. Fold it back together, taste for salt, and finish with the fresh herbs.
6. Serve hot over buttered potatoes.