½ cup chopped sweet onion (such as Vidalia or Maui) (1 medium)
½ cup orange juice
2 tablespoons honey
1 tablespoon cornstarch
1 tablespoon Worcestershire sauce
1 tablespoon Dijon-style mustard
1 clove garlic, minced
1 tablespoon sesame oil
9 ounces fresh kale (about 2 bunches), trimmed and coarsely sliced
8 ounces fresh baby portobello mushrooms or button mushrooms, sliced
1 red sweet pepper, coarsely chopped
1 tablespoon rice vinegar
Orange slices, halved (optional)
Preheat oven to 375°F. Coat a 2-quart square baking dish with cooking spray. In a very large nonstick skillet heat olive oil over medium-high heat. Add chicken to hot oil; cook about 12 minutes or until browned on all sides, turning to brown evenly. Transfer chicken thighs to the prepared baking dish, arranging in a single layer. Drain drippings from skillet, reserving about 1 teaspoon drippings in skillet.
Add chopped onion to hot drippings in skillet; cook and stir 4 to 5 minutes or until tender, scraping up any browned bits from the bottom of the skillet. In a small bowl whisk together orange juice, honey, cornstarch, Worcestershire sauce, mustard, and garlic; add to skillet. Cook and stir until thickened and bubbly; pour over chicken. Bake about 30 minutes or until chicken is no longer pink (180°F).
Meanwhile, use paper towels to wipe out the skillet. Pour sesame oil into skillet; heat over medium-high heat. Add kale, mushrooms, and sweet pepper; cook and stir about 10 minutes or until vegetables are crisp-tender. Add the rice vinegar; toss to combine. To serve, divide kale mixture among four serving plates. Arrange chicken on kale mixture. Whisk the cooking liquid in the bottom of the baking dish until combined; spoon over chicken. If desired, garnish with orange slices.