In a large bowl, whisk together soy sauce, rice vinegar, sesame oil, green onion and ginger, as well as fish sauce and chili, if using; set aside.
Sprinkle sesame seeds onto a plate. Press tofu into the seeds so that each slice is well coated. Grill tofu for four to six minutes on each side, until golden brown. (It's fine if the sesame seeds hiss and spit slightly, but don't let them burn.)
Meanwhile, steam sugar snap peas and asparagus for two to three minutes until tender-crisp. Drain and place in a bowl of iced water, then drain and dry on a clean tea towel.
To the large bowl with dressing, add sugar snap peas, asparagus, carrots and spinach. Toss to combine. Divide salad among four plates, top with grilled tofu slices and sprinkle with cilantro.
Tip: Firm tofu is sold in blocks. It's easier to grill than softer textures, and will hold its shape nicely.
Per side dish serving: 322 calories, 25 g protein, 19 g fat (3 g saturated fat), 19 g carbohydrates, 8 g fibre, 0 mg cholesterol, 144 mg sodium