- 1 large onion, finely chopped (2 cups)
- 3/4 stick (6 tablespoons) unsalted butter
- 3 skinless boneless chicken breast halves (6 oz each), cut diagonally into 1/2-inch-thick slices
- 1 1/8 teaspoons salt
- 3/8 teaspoon black pepper
- 2 tablespoons vegetable oil
- 2 small zucchini (10 oz total), cut into matchsticks (2 inches long by 1/4 inch thick)
- 2 large garlic cloves, minced
- 2 teaspoons curry powder (preferably Madras)
- 2 1/4 cups (18 fl oz) reduced-sodium chicken broth
- 1/2 cup heavy cream
- 1 1/4 cups couscous (8 oz)
- 2 1/2 tablespoons coarsely chopped fresh cilantro
- 1 lime, cut into wedges
- Cook onion in 2 tablespoons butter in a 10-inch heavy skillet over moderate heat, stirring occasionally, until softened, about 8 minutes, then reserve in skillet.
- Meanwhile, pat chicken slices dry and sprinkle with 1/2 teaspoon salt and 1/4 teaspoon pepper. Heat oil in a 12-inch heavy skillet over moderately high heat until hot but not smoking, then sauté chicken in 2 batches, turning occasionally, until just cooked through and golden brown, 3 to 4 minutes per batch, transferring chicken to a plate with tongs.
- Reduce heat to moderate and add 1 tablespoon butter, then cook zucchini with 1/8 teaspoon salt and a pinch of pepper, stirring frequently, until just tender, about 2 minutes. Transfer to plate with chicken and loosely cover with foil.
- Add garlic along with half of reserved onion to larger skillet and cook over moderate heat, stirring, until garlic is fragrant, about 2 minutes. Add 1 teaspoon curry powder and cook, stirring, 1 minute. Stir in 1 cup broth and bring to a boil, then boil until reduced by half, 2 to 3 minutes. Add cream and boil sauce, stirring occasionally, until just thick enough to coat back of a spoon, about 2 minutes. Set sauce aside in skillet.
- Reheat remaining onion in 10-inch skillet over moderate heat, then add remaining teaspoon curry powder and cook, stirring, 1 minute. Add 1 tablespoon butter and remaining 1 1/4 cups broth, then bring to a boil. Stir in couscous and remaining 1/2 teaspoon salt and 1/8 teaspoon pepper, then cover tightly and let stand off heat 5 minutes. Cut remaining 2 tablespoons butter into small pieces and stir into couscous. Let stand, covered, 1 minute.
- While couscous is standing, add chicken and zucchini to sauce along with any juices accumulated on plate and cook over moderate heat, stirring occasionally, until heated through, about 2 minutes. Season with salt and pepper and sprinkle with 1/2 tablespoon cilantro.
- Fluff couscous with a fork to break up any lumps, then stir in remaining 2 tablespoons cilantro and salt and pepper to taste. Serve with lime wedges.