Heat a small frying pan over medium high heat and add a little olive oil. Add the mushrooms, garlic, and parsley. Season with Salt and Pepper. Turn heat to low and cook about 15 minutes. Remove from heat and allow to cool.
In a large bowl, mix in the warrior bread mixture, eggs, water, and vinegar. Stir to combine and knead for one minute.
Preheat oven to 400
Put a piece of parchment paper down and put 1/4 of the dough on it. Put another piece of parchment paper on top and roll it out thin. Take the top paper off and put a filet in the center. Be sure to season the filet with salt and pepper and top it with a tablespoon of the mushroom mixture that was set aside. Using the bottom parchment paper, wrap the meat completely with the bread mix. Be sure to squeeze the dough tigh and seal it on all sides. Repeat with the remaining fillets.
Line a baking sheet with parchment paper and put the wrapped filets on it. Bake for at least 25 minutes.
Check the temperature with an instant read thermometer. For a nice medium rare center, you want to take it out of the oven when it has reached an internal temp of 130 (the temp will rise about 5-10 degrees while it rests.
Meanwhile, reduce the broth about 50% in a shallow pan over medium heat. Sprinkle on about half of the tapioca flour and whisk. Cook 2 minutes to thicken and add more flour if desired.
Serve the wellingtons with the gravy and your favorite veggie.