Make the meatballs, in a food processor, combine the tempeh and two types of bread crumbs. Pulse for a second to start breaking up.
In a small bowl, make a flax egg by combing the flax meal and 3 Tbsp. of water. Let sit for a minute to thicken.
Add the flax egg, hot sauce, seasonings and 1/4 C. of water to the food processor. Process, scrapping down the sides when needed until the mixture comes together and is a nice fine texture. You should be able to squeeze it together and it stays.
Once the meatball mixture is ready, form balls by grabbing a small amount of mixture and rolling it in your hands. Roll all of the mixture into balls.
Heat olive oil on medium high in a cast iron skillet if you have one, if not you can use a non stick pan. Place the meatballs in the skillet and cook on each side for 2-3 minutes until nice and brown.
Next, make the Buffalo sauce, melt the vegan butter in the microwave, usually takes about 30 seconds. Mix with the hot sauce. Whisk until fully combined. Once the meatballs are done, toss the meatballs in the buffalo sauce.
Toast the Hoagie rolls if you want, then place as many meatballs in the roll as you want. Top with celery if you like and vegan blue cheese sauce. You can also drizzle with more Buffalo sauce! Enjoy!