Preheat oven to 425°F (220°C). Line 2 large baking sheets with parchment paper or silicone mats. Place trimmed green beans into a mixing bowl.
In a small bowl, whisk together the non-dairy milk and ground flax seeds. Set aside for now.
Tear the slice of bread into small pieces and place in your food processor. Process until it becomes small breadcrumbs. Place the breadcrumbs into a separate small bowl, along with the nutritional yeast, cornmeal, garlic powder, and salt. Mix until combined, then transfer to a plate and spread evenly.
Pour the non-dairy milk and flax seed mixture on top of the green beans. Toss until the beans are well-coated. Transfer the green beans to the plate with the breadcrumb mixture, and gently turn the beans over, so the breadcrumbs stick as best as possible and all the beans are nicely coated.
Carefully spread out the beans onto the two baking sheets in a single layer.
Bake for 20–25 minutes, until toasty golden brown on the outside.
Serve with your favorite dipping sauce alone as a snack or as a side to a meal. See Notes for our suggestions.