1-Getting started with this vegan Wellington is as easy as following a few clear steps, beginning with preheating your oven and preparing your ingredients. First, preheat oven to 400°F (200°C) and line a rimmed baking sheet with parchment paper to set the stage for baking. Mix ground flax meal with water in a bowl and let it thicken for 10 minutes, which acts as a great egg substitute for binding.

2-Next, heat oil in a skillet over medium heat and sauté onion, celery, and carrots until softened, about 6-8 minutes, to build a flavorful base. Add garlic, thyme, sage, and rosemary; sauté for 1 minute to release their aromas, then toss in mushrooms and cook until softened and moisture evaporates, roughly 5-7 minutes. Stir in tamari sauce and cook for another minute before removing from heat to cool for 10 minutes.

3-Now, mash chickpeas in a large bowl, keeping some texture for a hearty feel, and combine with the mushroom mixture, breadcrumbs, walnut meal, flax mixture, Worcestershire sauce, tomato paste, salt, and pepper. Mix well and adjust if the filling is too wet by adding more breadcrumbs. Shape the mixture into a solid log that fits the pastry sheet, place it in the center, fold the pastry over, seal the edges with non-dairy milk if needed, and roll up the ends while trimming excess dough.

4-Flip the loaf so sealed edges are down on the baking sheet, brush with melted vegan butter, and score diagonal slits across the top to form a crisscross pattern. Bake for 30-35 minutes until golden, then let it rest for 10 minutes before slicing and serving with vegan gravy or sides. For more tips on baking, remember the preparation time includes 20 minutes prep and 40 minutes cook for a total of about 1 hour, making it manageable for working professionals or baking enthusiasts.