For glaze, heat oil in a medium saucepan over medium-high heat; cook onion in hot oil until golden brown. Reduce heat to low; stir in mustard, sorghum or honey, and vinegar. Simmer for 3 minutes. Stir in savory; cook and stir for 1 minute more. Set aside, reserving about one third of glaze to serve with ribs.
Cover and grill for 1-1/2 to 2 hours or until tender, brushing occasionally with glaze during the last 10 minutes of grilling. Heat and pass reserved glaze with ribs. Garnish with quartered oranges and fresh lemon verbena leaves, if desired. Makes 4 servings.