1. Whisk apricot preserves in saucepan over medium heat until melted and smooth, about 1 minute.
2. Add mustard and whisk until beginning to simmer, about 30 seconds.
3. Remove from heat.
4. Stir in rosemary.
5. Season with salt and pepper, if desired.
6. (Can be made 1 day ahead, and refrigerated. Stir over medium heat until warmed through.).
7. Heat oil in heavy large skillet over medium-high heat.
8. Add sausages and saute until browned and cooked through, about 10 minutes.
9. Transfer to saucepan with glaze.
10. Stir over medium heat until sausages are glazed, about 1 minute.
11. Serve warm.