Thai Red Curry Mussels

Name: Thai Red Curry Mussels
Ingredients: 2 teaspoons peanut oil, or canola oil; 2 medium cloves garlic, minced; 2 scallions, thinly sliced, whites and greens separated; Zest and juice of 1 lime; 1-2 teaspoons Thai red curry paste, (see Note); 1 14-ounce can “lite” coconut milk; 1 tablespoon brown sugar; 2 teaspoons fish sauce, (see Note); 4 pounds mussels, scrubbed and debearded (see Tip); 6 cups trimmed watercress, (1-2 bunches) or trimmed spinach; 2 tablespoons thinly sliced fresh basil, for garnish