Mash the tofu in a bowl with a potato masher or your hands. Heat the oil in a large non-stick or cast iron skillet on medium-high heat. Add mashed tofu, nutritional yeast flakes, onion powder, garlic powder, basil, parsley, turmeric, dill, and black salt.
Cook while stirring the tofu until the liquid has evaporated and it is golden, usually about 5 minutes.
Turn off the stove, add celery and green onion, and stir. Add vegan mayo; you can make your own or use store-bought.
You can serve it immediately on bread or rolls, or chill in the refrigerator in an airtight container for about 3 days.