1. Preheat oven to 425°.
2. Heat a medium saucepan over medium-high heat. Add 1 teaspoon oil to pan; swirl. Add shallots and ginger; sauté 1 minute. Add wine; bring to a boil. Cook 1 minute. Add broth, chili sauce, and mustard; bring to a boil. Cook until reduced to 3/4 cup (about 8 minutes). Stir in plums. Remove from heat.
3. Heat remaining 2 teaspoons oil in a large ovenproof skillet over medium-high heat; swirl. Sprinkle chicken with salt and pepper. Add chicken to pan, and sauté for 3 minutes. Turn chicken over; pour plum mixture over chicken. Bake at 425° for 6 minutes or until done. Let chicken stand 5 minutes. Sprinkle with green onions.