Total time: 40 minutes
For salad: Heat a heavy saucepan over medium-high heat. Rinse and drain quinoa, and add to pan. Stir until water has evaporated and quinoa begins to smell toasty, about 5 minutes. Add 3 cups water and salt; bring to a boil. Lower heat, cover, and simmer for 15 minutes, or until quinoa is tender and displays little white spirals. If excess water remains, drain and return to pan. Cover pan with a clean kitchen towel, replace lid, and let sit for 10 minutes. Transfer quinoa to a large bowl.
Meanwhile, pat tofu dry with paper towels, pressing to extract excess water. Cut into 1/2-inch cubes. Heat canola oil in a skillet over medium-high heat, then add tofu. Cook, stirring occasionally, until tofu is golden, about 5 minutes. Stir in soy sauce. Remove tofu from heat and combine with quinoa. Stir in peas or broccoli, cilantro, and spring onions or scallions.
To make dressing: Whisk together all ingredients. Toss with quinoa mixture.
To serve: Line plates with radicchio or lettuce leaves, if desired. Fill leaves with salad, and serve. This can be refrigerated up to 1 day.
Adapted from The Very Best of Recipes for Health (Rodale), by Martha Rose Shulman.