Heat water and salt in a medium saucepan; bring to boil. Add quinoa and cook until tender but still firm to bite, stirring occasionally, about 12 minutes. Remove from heat and let rest for 5 minutes. Transfer to medium bowl. Add mango, cucumber, red pepper and onion to quinoa. Mix well.

To make dressing: Blend oil, vinegar, chutney, black pepper, curry, mustard and ginger in a food processor. Add 1/4 cup dressing to quinoa mixture. Stir to coat. Spoon quinoa salad over spinach OR mix spinach with quinoa mixture. Drizzle with remaining dressing. Chill if desired.