To a medium saucepan, add the rinsed quinoa and 2 cups of water, bring to a boil over medium-high heat. Once it starts boiling, reduce heat to low and simmer for 15 minutes. Cover and simmer on low until quinoa has absorbed all of the water, then remove from the heat and let it rest for 5 minutes. Fluff with a fork and reserve.
While the quinoa is cooking, prepare the dressing by combining all lemon dressing ingredients to a small container with a tight lid and shake it to emulsify the mixture.
Add the cooked quinoa, sun-dried tomatoes, spring onions, peas, hazelnuts, salt and pepper to a large mixing bowl and drizzle lemon dressing over to taste. Toss to combine.
Taste for seasoning and adjust salt and pepper, if desired.
Notes
Nutritional calculation includes all of the dressing as listed. To reduce both calories and fat, apply only half of the dressing and reserve the remainder for later use.