Season pork with salt and pepper. In a 12-inch skillet heat olive oil over medium-high heat. Add pork and onion to skillet. Cook for 3 minutes; turn pork and onions. Cook for 3 minutes more.
Meanwhile, in a small microwave-safe bowl combine preserves, mustard, the water, paprika, and nutmeg. Heat in microwave on 100 percent power (high) for 1 to 2 minutes or until melted. Pour over pork in skillet. Reduce heat to medium. Cook, covered, for 10 minutes or until pork is cooked through (slightly pink in center).
Divide pork and onion mixture among serving plates. If desired, top with sage.