Vegan Mushroom Lentil Wellington Recipe

Prepare vegetables

Heat a large skillet over medium heat. Add olive oil. Once shimmering, add the diced onion, carrot, and celery. Sauté, stirring occasionally, until softened and beginning to brown, about 6–8 minutes.

Add the minced garlic and cook for 30–60 seconds, stirring constantly so it doesn’t burn.

Increase heat to medium-high and add the finely chopped mushrooms. Cook, stirring frequently, until the mushrooms release their liquid and it evaporates and the mushrooms begin to brown, about 8–10 minutes. This step concentrates flavor and prevents a soggy Wellington.

Stir in dried thyme, smoked paprika, and soy sauce/tamari. Cook 1–2 minutes to allow flavors to meld and liquid to reduce slightly.

Add the cooked lentils, chopped walnuts (if using), and pulsed oats. Stir to combine and cook 2–3 minutes to warm through and let oats absorb moisture.

Remove skillet from heat. Stir in nutritional yeast, chopped parsley, lemon juice, salt, and black pepper. Taste and adjust seasoning. Let the mixture cool at least 15 minutes (or to room temperature) so it firms up for easier assembly.

Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper. If using frozen puff pastry, ensure it is fully thawed in refrigerator and brought to a cool but pliable temperature before rolling.

On a lightly floured surface, roll the puff pastry sheet into a rectangle roughly 12 x 10 inches (30 x 25 cm), keeping it about 1/8-inch thick. Trim edges if necessary to create an even rectangle.

Spoon the cooled mushroom-lentil filling down the center lengthwise, forming a log roughly 3–4 inches wide and leaving a 1–inch border on each long side and 1.5–2 inches on each short end.

Brush the long pastry edges with aquafaba or non-dairy milk to help seal. Fold the pastry over the filling from the long sides, overlapping seam slightly. Press seam gently to seal, then flip the seam side down onto the prepared baking sheet so seam is on the underside.

Tuck in the short ends to enclose the filling. Use a sharp knife to lightly score decorative slits on top (do not cut all the way through). If desired, brush the Wellington with more aquafaba/milk and sprinkle with sesame or poppy seeds.

Place the assembled Wellington in the preheated oven and bake 25–30 minutes, or until pastry is puffed and deep golden brown. Rotate the baking sheet halfway through for even browning.

If the pastry browns too quickly, tent loosely with foil for the remaining baking time.

Remove the Wellington from oven and let rest on the baking sheet for 10–12 minutes — this helps the filling set and makes slicing cleaner.

Transfer to a cutting board and slice into 6–8 portions with a sharp serrated or chef’s knife. Serve warm with vegan gravy and garnish with fresh thyme sprigs.