With a wide vegetable peeler, shave the tofu block in very fine slices.
In a container, mix the maple syrup and soy sauce. Add in your finely shaved tofu and toss it by hand delicately to cover all of them in the marinade. Allow to sit in the fridge for at least an hour.
Make the High Protein Cheese Sauce per the recipe link above.
Make the High Protein Vegan Mayo per the recipe link above. You could also use store bought vegan mayo but your macros and calories will vary.
In a medium heat skillet, dump out the tofu slices and remaining marinade and cook, stirring regularly, for about 20 minutes.
In a separate medium heat skillet, cook the mushrooms and onions for 10 - 15 minutes, stirring often to avoid burning.
Slice the hoagie buns in half and broil in the oven (cut-side facing up) until lightly browned and crispy.
Spread mayo on one half the bun. Then add the cooked tofu on top, followed by the cooked mushrooms and onions, and the cheese sauce.