Rinse the quinoa well in a bowl of cool water and drain. Bring the quinoa, 1/2 tsp. salt, and 3 cups water to a boil in a medium saucepan over high heat. Cover, reduce the heat to medium low, and simmer until the water is absorbed and the quinoa is translucent and tender, 10 to 15 minutes. (The outer germ rings of the grain will remain chewy and white. Some germ rings may separate from the grains and will look like white squiggles.) Immediately fluff the quinoa with a fork and turn out onto a baking sheet to cool.
When cool, fluff the quinoa again and transfer to a large bowl. Add the tomato, parsley, cucumber, scallion, oil, lemon juice, cumin, cinnamon, and 1 teaspoon salt. Toss well. Cover and refrigerate to let the flavors mingle, at least 2 hours or overnight.
Before serving, let sit at room temperature for 20 to 30 minutes. Stir in the mint. Taste and add more oil and lemon juice (you’ll probably need at least 1 tablespoon of each), and more salt as needed.
nutrition information (per serving): Size: per 1/2 cup; Calories (kcal): 130; Fat (g): 8; Fat Calories (kcal): 70; Saturated Fat (g): 1; Protein (g): 3; Monounsaturated Fat (g): 6; Carbohydrates (g): 13; Polyunsaturated Fat (g): 1; Sodium (mg): 110; Cholesterol (mg): 0; Fiber (g): 2.