Cook ½ cup quinoa in 1 cup vegetable broth according to package instructions. Let sit covered for 5 minutes, then fluff with a fork.
Toss 1 medium zucchini and 1 small fennel bulb with 1 tablespoon olive oil, salt, and pepper. Grill or sauté until tender.
In a bowl, whisk together remaining olive oil, 1 teaspoon vinegar, lime zest and juice, 1 teaspoon coriander seeds, salt, and pepper.
Stir in ¼ cup fresh mint (reserve some for garnish).
Toss quinoa with dressing.
Divide among plates, top with vegetables and 3½ oz smoked salmon.
Garnish with fennel fronds, mint, and extra lime zest.