1. Mix boiling water into textured soy protein granules and let sit for 15 minutes. In another bowl, mix together arrowroot, oats, onion powder, garlic powder, flour, soy sauce, ketchup, salt, and pepper.
2. Once textured soy protein is rehydrated, add oat mixture to textured soy protein and mix well. Cover and place in the fridge for 15 minutes to allow textured soy protein to firm up.
3. Remove textured soy protein and divide into quarters. With your hands, roll each quarter into a ball and flatten into a patty shape.
4. Lightly brush each side with oil and add some oil to a large skillet. Heat oil until a drop of water sizzles, then add patties to the skillet. Cook 3-4 minutes on each side.
Assemble the sandwich with lettuce, pickles, and tomatoes. Enjoy!