1. Put the wild rice in a saucepan and cover with plenty of salted water. Bring to a boil, then reduce the heat to a gentle boil and cook the rice until it’s tender, about 45 minutes.
2. While the rice is cooking, preheat the oven to 375ºF (190ºC). Drizzle a few spoonfuls of olive oil on a rimmed baking sheet. Spread the cubed vegetables over the pan and season well with salt and freshly ground pepper.
3. Toss the vegetables with the olive and spread them on the baking sheet in an even layer. Bake for 30 to 45 minutes, stirring once or twice during cooking, until the vegetables are fully cooked.
4. When the rice is done, drain it well and toss it in a large bowl with the cooked vegetables and let cool to room temperature. Once cool, stir in the onions and herbs.
5. Make the lemon-tahini dressing by stirring together the tahini, lemon juice, water, garlic, and soy sauce, then pour it over the salad and stir it in well. Taste, and add a bit more salt and lemon juice, if desired.