Boil: Add unpeeled beets and balsamic vinegar to a large pot. Cover with water so beets are submerged. Cover and bring to a simmer, then cook for 30 minutes, or until beets are fork tender.
Peel: When finished, allow them to cool slightly then peel.
Mushroom Pâté
Flavor Base: Heat butter and oil in a large saute pan over medium heat. Add garlic, shallots, thyme, and rosemary. Cook until shallots are soft and fragrant, about 3 minutes.
Mushrooms: Add sliced mushrooms and continue cooking until mushrooms release their moisture and are soft, about 7 to 10 minutes.
Blitz: Add cooked mushroom mixture, ricotta, and salt to a food processor. Blitz until a smooth paste is formed. Chill in the fridge until ready to assemble.
Assembly
Dough: Thaw puff pastry dough completely. Layer a few pieces of plastic wrap onto your counter to work on top of (this will make rolling easier). "Glue" the two pieces of puff pastry together by pressing the edges together with a bit of water as glue, creating a long rectangular piece of puff pastry.
Pâté: Spread about half of the mushroom pâté onto the pastry dough, leaving about 1 inch on all sides free.
Breadcrumbs: Stir together breadcrumbs and 1/4 tsp of salt and pepper. Sprinkle half of it on top of the pâté.
Beets: Arrange beets in a line lengthwise on the pastry dough. Slather the beets with remaining pâté, working it in between the beets. Sprinkle with remaining breadcrumbs.
Roll: Carefully stretch the dough over the beets, pinch it together at the top to form an enclosed log. Mend any tears or gaps by using a bit of water as glue. Seal by pressing a water-moistened fork over the creases.
Chill: Wrap the plastic wrap around the log, then let chill in the fridge for 1 hour (up to 8 hours).
Cook: Preheat oven to 400°F (204°C). Transfer Beet Wellington to a parchment-lined baking sheet, seam-side down. Brush whisked egg all over the pastry dough. Use a sharp knife to cut slits into the top to allow steam to escape. Bake for 40 minutes, or util golden brown and crispy.
Serve: Allow to cool slightly, then move to a platter, slice, and serve! Delicious drizzled with balsamic reduction (glaze) and crumbled goat cheese.
Video
Notes
Store leftovers in an airtight container in the fridge for up to 5 days.Make ahead by boiling beets and making mushroom pâté in advance (up to 2 days in advance). Once assembled, the wellington can chill in the fridge for up to 8 hours.