1. Bring a large pot of salted water to a boil. Add the beans, cooking until al dente, firm to the bite, yet tender and tasting very sweet but not raw green.
2. Transfer to a colander and drain. Cool immediately under cold running water.
3. Transfer to a dish, cover loosely with plastic wrap and store under refrigeration while making the dressing.
To cook the Couscous:
1. In a small saucepan bring 1-1/4 cups water to a boil. Add the turmeric and season with salt and black pepper.
2. Place the couscous in a medium bowl and pour the hot liquid over. Cover and allow to sit until all the liquid has been absorbed, about 10 minutes.
3. Transfer to a cookie sheet to cool. Stir to fluff with a fork. Adjust seasonings to your taste.
To make the Dressing:
1. In a medium non stick skillet heat 2 tablespoons of the olive oil over medium heat.
2. Add the garlic and ginger, cooking slowly until tender but not browning about 5 minutes.
3. Add the sherry vinegar and lemon juice, turning the heat to high and bringing to a boil. Cook until reduced to about half a cup.
4. Remove from the heat and allow to cool to room temperature. Transfer to a blender and puree until smooth.
5. Leave the blender running and slowly add the remaining olive oil. Adjust the seasonings with salt and pepper. Add the chives.
6. Transfer to a sealed container and refrigerate for up to 3 days, if not using immediately.
Put it all together:
1. In a large bowl, combine the beans, onion, red pepper and greens with about half of the dressing to coat.
2. Add the couscous and the remaining dressing, tossing thoroughly.
3. Add half of the mint and toss to combine.
4. Transfer to a large serving bowl and mound high.
5. Top with the remaining mint and a generous sprinkle of black pepper. Serve slightly chilled for the fullest flavor.