Add all ingredients to the slow cooker, except the corn starch/water mixture and Grands biscuits. Stir to combine and cook on low for 8 hours.
When there is 1 hour left, whisk the cornstarch and 1/4 cup of water together in a small mixing bowl to form a cornstarch slurry. Stir in the cornstarch slurry to thicken.
When 15 minutes left, bake or air fry the Grands biscuits according to package instructions.
Serve vegan chicken pot pie warm with grands biscuits on top.
Freezing Instructions
To freeze before cooking: In a large, gallon-sized freezer bag, add the rinsed and drained chickpeas, diced onion, minced garlic, frozen vegetable mix, sliced celery, potatoes, milk, and spices. Seal tightly, removing as much excess air as possible. Then before cooking, transfer the frozen pot pie to the slow cooker bowl and add the broth and vegan sour cream and follow cooking instructions as usual.
To freeze after cooking: Allow the pot pie filling to cool completely, then transfer to freezer bag or freezer cubes (My preferred method). Thaw overnight in the refrigerator, or heat over low heat in a pot on the stove top. The biscuits can also be frozen separately, and reheated in the oven or air fryer until flaky and soft again.
Notes
Possible Add-ins
Add nutritional yeast: For a cheesier vegan pot pie, add up to 1/4 cup nutritional yeast.
Homemade biscuits: I usually use canned biscuits that I purchase on super discount at Grocery Outlet for $0.50, but full-priced biscuits at regular grocery stores can be quite pricy (I've seen them for upwards of $9 a can! WHAT!). Instead, go the homemade route and make hot fluffy Vegan Buttermilk Biscuits from scratch for a fraction of the price.
Leftover potatoes? If you have leftover Oven Roasted Potatoes or Baked Potatoes on hand, they can be used in this delicious vegan pot pie. Simply stir them into the creamy filling with the cornstarch slurry and enjoy!
TIP: Canned biscuits and cinnamon rolls always say on the can that they should not be frozen. Despite this, I have frozen both of these products and it is COMPLETELY FINE! They are slightly less puffy once baked, but it's hardly noticeable. Don't be afraid to stock up when they are on major sale and freeze the extras!