Preheat the oven to 425 degrees.
In a medium bowl, whisk together 3/4 cup of almond milk with lemon juice. Let sit for 5 minutes to allow some curdling. Then whisk in pumpkin puree.
In a large bowl, mix the dry ingredients for the dough. Cut cold butter into the mixture until well combined. Mix in chopped sage.
Stir in the pumpkin mixture, a little at a time, until lightly combined. It should be lightly sticky.
Turn out onto a lightly floured surface, dust with flour, knead lightly a few times. Gently press down until about an inch thick. Using a small glass or a dough cutter, cut out the biscuits.
Bake for 13-17 minutes or until fluffy and golden brown. These take a little longer to bake than traditional biscuits because the pumpkin adds extra moisture.
In a non-stick skillet, saute onion, garlic, and a pinch of salt for 5-7 minutes. Then whisk in corn starch and the vegetable broth.
Stir in almond milk, diced vegetables and bay leaves. Simmer for about 10 minutes to thicken. Thicken with more cornstarch if needed.
Take out the bay leaves and transfer the filling into an 8×8 baking dish or a 9-inch round pie plate.
Top with unbaked biscuits and brush the tops with melted vegan butter. Place on a baking sheet, and bake about 15-20 minutes, until the biscuits are golden. Let cool slightly before serving.