Heat oven to 400°F. In a large oven-safe skillet, cook the diced onion and small-diced potatoes in the oil for 8 minutes.
Sprinkle in the flour and thyme and stir 1 minute, then slowly whisk in the broth and oat milk. Simmer until thick, about 5 minutes.
Stir in the frozen vegetables and drained beans and season well with salt and pepper.
Lay the pie crust over the skillet, tuck the edges in, and cut a few slits in the top.
Bake 25 minutes until the crust is golden. Let it cool 10 minutes so the filling sets before serving.
Check the crust label: many store crusts are made with vegetable shortening and are vegan, but some use butter.
Photo: Ella Olsson / Unsplash