Combine oil, vinegar, preserves, red pepper flakes, salt and pepper in a small bowl. Whisk well to combine.
Brush onion slices with olive oil. Place on grill pan and grill, turning occasionally, until tender, about 10 minutes. Break into rings and set aside. Brush peach halves with olive oil. Place on grill pan and grill, turning occasionally, until tender and caramelized, about 2 minutes. Slice each peach half into 4 pieces.
Place greens and arugula in salad bowl. Top with bacon, onion rings, peach slices and crumbled goat cheese. Toss salad with half the vinaigrette and taste. Add more vinaigrette if desired.