Make the wrap:
Blend the tofu, chickpea flour and nondairy milk into a smooth, thick paste. If needed, add some more milk. Set aside. This is your "egg" wash.
Mix together the flour and salt and then add enough water to knead into a soft, pliable dough. Set aside for at least 30 minutes.
Divide the dough into six pieces.
Roll each piece into a smooth ball, flour the surface and your rolling pin, and roll into a circle about four inches in diameter.
Spray lightly with oil, fold it once and then once more, and then roll out into as thin a circle as you possibly can. Mine end up about eight inches in diameter.
Heat a griddle and place the wrap on it. When bubbles start to appear, brush on the "egg" wash with a pastry brush. Spray over it lightly with oil and flip the wrap. Let it cook until golden-brown spots appear on the underside. Remove and set aside, covered with a kitchen towel.
Make the filling;
Place the tofu in a microwave-safe dish and zap two minutes. Drain out accumulated water, flip the tofu brick over, and zap another two minutes. When the tofu is cool enough to handle, cut into six slices. Place the tofu slices in a baking pan sprayed with oil. Lightly spray the top of the tofu. Bake in a preheated 350-degree oven about 45 minutes or until the tofu is really chewy. Cut into a small dice and set aside.
Heat the oil. Add the cumin seeds and, when they sputter, add the onions and saute, stirring frequently, until the onions start to brown.
Add the ginger and garlic and stir-fry for a few seconds.
Add the tomatoes, coriander and cumin powder, paprika and turmeric. Let the mixture cook until the tomatoes lose most of their moisture and become a couple of shades darker.
Add the bell pepper and mushrooms and tofu and mix thoroughly. Let it cook until the peppers are slightly tender but still have a bite and all the moisture in the mixture has evaporated. Add the chaat masala or lemon juice and salt to taste.
Turn off heat.
Place some filling in the center of the wrap, add some raw onions or spring onions and tomatoes for an authentic experience, and wrap the Kathi roll tightly. Place seam side down, cut into two or three, and serve warm.