Sprinkle chicken with the thyme, salt and pepper. In a large skillet, brown chicken in oil. Meanwhile, drain pineapple, reserving the juice. Cut pineapple rings in half and set aside.
Combine cornstarch and 2 tablespoons juice until smooth; set aside. Combine the mustard, honey, garlic and remaining pineapple juice. Add to pan; bring to a boil. Reduce heat; cover and simmer for 15-20 minutes. Remove chicken and keep warm.
Stir cornstarch mixture. Gradually add to pan; bring to a boil. Cook and stir for 2 minutes or until thickened. Return chicken to pan. Top with pineapple; heat through. Serve with rice. Yield: 4 servings.