1. Preheat oven to 425°.
2. Heat a large ovenproof skillet over medium-high heat. Add oil; swirl to coat. Sprinkle chicken with 1/4 teaspoon pepper and 1/8 teaspoon salt. Add chicken to pan; cook 5 minutes. Turn chicken; place pan in oven. Bake at 425° for 7 minutes or until done. Remove pan from oven. Place chicken on a plate; keep warm.
3. Return pan to medium-high heat. Add carrot, shallots, thyme, and garlic to pan; sauté 2 minutes. Add wine to pan; cook 2 minutes or until liquid is reduced by half, scraping pan to loosen browned bits. Add stock to pan; cook 2 minutes or until slightly thickened. Stir in 1 1/2 teaspoons butter and Dijon mustard.
4. Bring a large saucepan of water to a boil. Add haricots verts; cook 3 1/2 minutes or until crisp-tender. Drain. Place haricots verts, remaining 1/8 teaspoon pepper, remaining 1/8 teaspoon salt, and remaining 1 1/2 teaspoons butter in a bowl; toss to coat. Serve haricots verts with chicken and sauce.