Preheat the oven to 400F. Toss the asparagus pieces in the olive oil. Place them onto a parchment or foil lined baking sheet and sprinkle them with a generous amount of salt and pepper. Roast for 15-20 minutes, or until they're tender and a little crispy on the outside, stirring them halfway through. Set the roasted asparagus aside.
While the asparagus roasts, bring the quinoa and water to boil in a medium sized pot. Reduce the heat to a simmer, and cover the quinoa. Cook for 15 minutes, or until all of the water is absorbed. Fluff the quinoa gently with a fork and return the lid to the pot. Allow the quinoa to rest for 10-15 minutes.
Whisk together the dressing ingredients. Transfer the quinoa and asparagus to a large mixing bowl and add the peas. Add the dressing and toss the salad gently, so that all of the dressing is incorporated. Check the salad for seasoning and add more salt, pepper, and lemon as desired.
Divide the salad onto four plates. Top each with a quarter cup of chopped pea shoots, and serve.