Preheat oven to 350 F. Lightly grease or line a cookie sheet with parchment paper and set aside. Whisk non-dairy milk and lemon juice together until foamy with bubbles. In a medium bowl, mash chickpeas with a fork or potato masher until coarse. You don't want any whole beans left, but don't overly mash them so that they are pureed and resembling refried beans. Alternatively, you can pulse the beans in a food processor 10-15 times and transfer processed chickpeas to the bowl. Add in TVP, crumbs if using, vital wheat gluten, mustard, spices and agave. Add in 1/4 cup water and mix with a spoon. Gluten should form almost instantly. Turn out onto a clean surface and knead for about a minute, getting out any excess bubbles and making sure the gluten strands form. Mold the mixture into ball and set aside. Pour cornflakes into a separate bowl and mash until very crumbly, like thick and slightly bigger bread crumbs and set aside. Re-whisk non-dairy milk and then pour mixture into a shallow bowl. Break off bouncy ball-sized portions of the gluten and flatten in the palm of your hand to it resembles a nugget shape. Dip into the non-dairy milk mixture so that it's coated on both side then press into flakes on each side, making sure it's completely coated. Place nugget on a cookie sheet and repeat with all nuggets. Bake nuggets for 10 minutes, flip and bake another 10-15 minutes, until nuggets are firm and crispy.