Preheat oven to 450°. In a bowl, whisk flour, baking powder, baking soda and salt. In a separate bowl, combine soymilk and vinegar. Using your fingers or a pastry cutter, cut solid coconut oil into flour mixture until dough resembles pea-size crumbs. Stir soymilk mixture into flour mixture with a fork until combined. Using a 1/4-cup measure, drop dough into 12 mounds onto a baking sheet. Bake biscuits until golden on top, about 15 minutes. Remove from oven.

For the gravy, in a large sauté pan over high heat, sauté mushrooms in olive oil until mushrooms release all their liquid and begin to brown, 15-20 minutes. Remove mushrooms to a plate; set aside. In the same pan over medium-low heat, sauté onion, yeast, sage, garlic, paprika, pepper flakes, fennel seed and coriander for 5 minutes. Stir or whisk in ground chia seeds and 3 cups soymilk. Let gravy simmer over medium heat until thickened to desired consistency, about 8 minutes. Stir in soy sauce and mushrooms. Season with salt and pepper.

To serve, split biscuits and top with gravy. Garnish with fresh sage leaves.