Make the lemon garlic vinaigrette. In a medium bowl, whisk together the lemon zest, lemon juice, garlic, Dijon mustard, agave, salt, and pepper. Once that's combined, slowly start pouring in the olive oil, whisking as you go. Once you've poured all of the oil in and the vinaigrette is emulsified, give it a little taste. Adjust the level of seasoning if you need to, and then set it aside.
Preheat the oven to 400°F. Line a baking sheet with parchment and scatter the pine nuts over the surface. Slide the baking sheet into the oven while it's preheating to toast the pine nuts for about 5 minutes, or until lightly golden. Set them aside to cool.
In a small saucepan, combine the quinoa, water, and a pinch of salt. Cover the saucepan with a lid and place it over medium high heat. Bring the quinoa to a boil and then lower the heat to a simmer. Cook until the quinoa has absorbed all of the water and the little tails are sticking out, about 13-15 minutes. Once cooked, remove the quinoa from the heat and let it cool in the saucepan for a couple minutes.
Transfer the cooled toasted pine nuts from the baking sheet to a small bowl.
Place the diced asparagus and broccoli on the baking sheet. Toss the vegetables with olive oil, the za'atar spice blend, salt and pepper. Once everything is evenly coated, spread the vegetables out in a single layer. Slide the baking sheet into the oven and roast for 10 minutes, or until the vegetables are bright green and slightly softened. Remove the baking sheet from the oven and allow the vegetables to cool a bit.
Transfer the cooked quinoa to a large bowl and toss with 3 tablespoons of the vinaigrette. Then, add the roasted asparagus and broccoli, chopped dill, chopped chives, and the rest of the vinaigrette to the bowl. Sprinkle everything with a big pinch of salt and lots of freshly ground black pepper. Use a serving spoon or spatula to toss the quinoa salad together. Once it's all combined, give it a taste to see if you'd like to adjust the seasoning at all.
Once the salad is to your liking, serve it up with the pine nuts, soft vegan cheese, and reserved lemon zest sprinkled on top. Leftovers keep in a sealed container for up to 5 days.