1. Heat oil in a 2-quart saucepan over medium heat; add garlic and cook 30 seconds. Add kale and stir; cover and cook 5 minutes, until kale is almost tender. Add water and salt to kale; bring to a boil. Stir in couscous; remove from heat and let stand 5 minutes. Stir in wine and butter.
2. Meanwhile, cut salmon crosswise into 4 equal strips. Heat oil in a large skillet over medium-high heat. Sprinkle fish with salt and pepper; place in skillet skin side down. Cover and cook 6 to 8 minutes, just until cooked though.
3. Divide couscous among 4 serving plates. Top each with a salmon fillet. Serve with lemon wedges and green beans, if desired. (Nutrition facts are based on per serving without green beans.)