Bring three quarts water to a simmer, and season to taste with 3 Tbsp kosher salt. Add quinoa, and simmer until tender, about 40 minutes. Drain quinoa, and rinse with cold water. In a bowl, mix quinoa with scallions. Add 1 Tbsp olive oil, 11⁄2 tsp lemon juice, and 11⁄4 tsp kosher salt; stir. Bring two quarts water to simmer, and season to taste with 11⁄2 Tbsp kosher salt. Gently lower egg into water; simmer 10 minutes. Drain egg; cover with ice water. When cold, peel and slice in half. Place kale in a bowl, and massage with hands till slightly wilted. Season with 1 tsp lemon juice, zest of 1⁄2 lemon (using a microplane), and 1⁄4 tsp kosher salt. Scoop out flesh of avocado half, and cut into two wedges. Carefully season each wedge with olive oil and sea salt. Divide sardine fillets and avocado wedges on two plates. Spoon quinoa salad onto plates. Add kale salad, near quinoa. Place an egg half on each plate. Top with parsley.