These sheet pan mushroom birria tacos are vegan, bold, and ready faster than the classic. Portobello and shiitake mushrooms, crispy tortillas, and a rich consommé.
In a large bowl, combine vegetable oil, oregano, cumin, garlic powder, smoked paprika, cinnamon, salt, and pepper. Use your hands to tear the mushrooms into pieces and coat in the spice mixture. Transfer to a large parchment-lined sheet pan and roast in oven for 10 to 12 minutes.
After 12 minutes, check on the mushrooms. If mushrooms have released a significant amount of liquid, carefully pour it into a large liquid measuring cup. Continue roasting the mushrooms for another 10 to 15 minutes.
Pour additional mushroom broth or beef-flavoured broth into the measuring cup until you have a total of 1 ½ cups of liquid. Bring this to a boil in a small saucepan over medium to high heat. Turn down the heat slightly if needed to keep it at a low simmer and add chipotle peppers in adobo, tomato paste, apple cider vinegar, and brown sugar. Continue simmering until reduced and you have about 1 cup of liquid. If you can’t get the chipotle pepper broken up with a fork once cooked you can place an immersion blender in the pot to get the broth less chunky.
After mushrooms start to brown, stir and push all the mushrooms to one side of the sheet pan or remove them to a plate to make room for the tortillas. Lay out 10 to 12 tortillas and either brush some of the consommé on both sides of the tortillas or dip them in the broth/consommé quickly to coat. This will warm the tortilla and make it more flexible, as well as encourage browning and crisping during baking. You may have to roast the tortillas in batches depending on how large your sheet pan is.
Divide the vegan cheese shreds evenly onto one half of each tortilla and top the cheese side with ¼ cup of the roasted mushrooms, additional pickled jalapeños, and sliced red onion. Gently fold each tortilla in half and press so it stays folded. Bake in the oven for 15 more minutes, flipping halfway and basting the other side with more mushroom liquid with a brush, until the tacos are crispier and the cheese is melted.
Garnish tacos with cilantro leaves and serve with the remaining consommé on the side for dipping.