Place the lentils in a saucepan, cover with an inch of water, bring to a boil, cover, and continue cooking 10-15 minutes or until lentils are tender but not mushy. Drain and set aside.
Preheat the oven to 425 degrees Fahrenheit/220 degree Celsius.
Heat the oil in a skillet. Add the carrots, celery, onions and garlic along with a dash of salt and ground black pepper. Saute, stirring frequently, until the veggies start to caramelize.
Add the mushrooms, saute for a minute, then add the wine. Continue to cook, stirring often, until the wine has evaporated and the mushrooms are browned.
Add the herbs, soy sauce or tamari, dijon mustard and salt and ground black pepper to taste.
Add the lentils and continue cooking until there is no visible liquid in the skillet.
Place the filling in a spot where it can cool quickly. I put it in a bowl and place it in the fridge.
Preheat oven to 425 degrees Fahrenheit/220 degrees Celsius.
Roll out one of the puff pastry sheets to 11 X 13 inches on a lightly floured surface.
Divide the lentil mixture in two and form each into a loaf. Place one loaf in the center of the rolled out puff pastry sheet.
Fold the puff pastry over the loaf and press in the seam. Use a little water to moisten the edges, to help the seams stick.
With the seam side down tuck in the ends and seal them so you have a neat-looking, fully wrapped log. Repeat with the second sheet of puff pastry and the remaining lentil-veggie mixture.
Using a sharp knife, score the top of the log in a decorative pattern-- I did a crosshatch. You can coat the top with an optional wash of a teaspoon of oil mixed with a teaspoon of non-dairy milk for better color.
Place the wellington loaves on a baking sheet lined with parchment paper.
Place the baking sheet in the preheated oven and bake the wellington logs for 45 minutes. Remove, let the wellingtons stand for about 10 minutes, then slice and serve.