- Whisk vinegar, curry powder, garlic, salt and pepper in medium bowl to blend. Gradually whisk in olive oil. Set aside.
- Bring 2 quarts salted water to boil in a heavy large saucepan. Add the quinoa and let gently boil for 10 minutes. Add the lentils and kohlrabi leaves. When water returns to boil, gently boil until lentils are tender but not too soft, about 6 minutes. Drain; rinse under cold water to cool. Drain again.
- Bring 11/4 cups water to boil in same saucepan. Add 3 tablespoons dressing, sprinkle with salt, then stir in couscous. Cover pot, reduce heat and let simmer for 8 minutes. Transfer couscous to medium bowl. Fluff couscous with fork to separate grains and cool slightly. Season to taste with salt and pepper.
- Meanwhile, transfer lentils to large bowl. Add 1/2 cup dressing, diced kohlrabi bulb, and chopped green onions; toss to coat. Season mixture to taste with salt and pepper.
- Arrange baby spinach leaves over large rimmed platter. Drizzle spinach with 2 to 3 tablespoons remaining dressing. Sprinkle spinach leaves with salt and pepper. Mound lentil mixture in center of platter over spinach leaves. Stir mint into couscous. Spoon couscous around lentils and serve with remaining dressing. Serves 8 as a main course.