Place the seasoning mix ingredients in a small bowl, whisk to combine, and set aside.
Heat the oil in a large nonstick sauté pan over medium-high heat. Once the oil is hot, add the mushrooms and tofu, and cook, stirring often, until most of the liquid has cooked out of the mushrooms and the tofu starts to crisp around the edges, 10 to 12 minutes. Reduce the heat to medium. Add the white onion, water chestnuts, carrot, garlic, and ginger, mixing to combine. Season the mixture with the seasoning mix and continue to cook until the white onion is slightly translucent, and the garlic is fragrant, 4 to 5 minutes. Add the green onion, give it another mix to combine, and remove from the heat. Let the filling cool at room temperature about 10 minutes before assembling summer rolls.
To assemble summer rolls, fill a large bowl with cool water. Submerge your rice paper into the bowl, rotating if you need to, until it's just softened and pliable, about 12-15 seconds. Place the rice paper roll on a lightly dampened, clean work surface.
Place a lettuce leaf towards the bottom middle of the rice paper, followed by a couple tablespoons of the filling, cilantro and some wonton strips.
Gently fold over once, tuck in both sides, then continue to gently roll up tightly until the seam is sealed – it’s sticky so it will seal itself. Repeat until you have about 15 rolls.
Cut in half, and serve immediately with toasted seeds, green onion, and spicy soy sauce! Enjoy!