The keys to perfectly seared scallops are a very hot skillet and not overcrowding the pan. Simmer scallops in the stew only until they are done so that they remain tender. For an elegant presentation, set aside some of the sautéed leek to garnish each serving.
1. Pat scallops dry with a paper towel; lightly coat scallops with cooking spray. Heat a large nonstick skillet over medium-high heat. Add one-third of scallops; sear 2 minutes on each side or until lightly browned. Remove scallops from pan. Repeat procedure twice with remaining scallops.
2. While scallops cook, heat olive oil in a large saucepan coated with cooking spray over medium-high heat. Add leek and garlic; sauté 4 minutes or until tender. Add wine and next 5 ingredients; bring to a boil. Reduce heat, and simmer, uncovered, 5 minutes. Add scallops, and simmer 3 minutes. Remove from heat; stir in half-and-half.
3. Combine cilantro, breadcrumbs, and lemon rind in a small bowl; stir well. Ladle stew into individual bowls; top with breadcrumb mixture.