In a food processor, blend the toasted hazelnuts into a fine meal.
Add the garlic, lemon juice, salt, and parsley, and process for 1 minute.
Drizzle in as much oil as needed to create a smooth paste, scraping the sides occasionally.
Cook the quinoa:
Bring the water to a boil in a medium saucepan.
Stir in the quinoa and cook uncovered over medium heat for 10 minutes.
Drain and transfer to a large bowl.
Mix with the prepared pesto and set aside.
Prepare the sprouts:
In a large saucepan, heat the canola oil over medium heat.
Add the chopped onion and cook until translucent, about 4 minutes.
Stir in the Brussels sprouts, lemon juice, and salt.
Cook until tender, about 6 to 8 minutes.
If the sprouts stick to the pan, deglaze with sherry wine or water.
Assemble and serve:
Add the Brussels sprouts mixture to the quinoa with pesto.
Serve warm.
Notes / Tips / Wine Advice:
Serving Tip:Pair with a side of roasted vegetables or a simple green salad for a complete meal.Wine Advice:A crisp Sauvignon Blanc or a light Pinot Gris complements the nutty and citrusy flavors of the dish.