If you can grill a steak, you can grill a duck breast.
But, all duck breasts are not created equal. I am a devotee of the Moulard magret. The Moulard duck is a cross between the Muscovy duck and the Pekin duck. Since it is the duck that is raised for foie gras, the breasts are large and have an average weight of 14-16 ounces. One breast can easily serve 2 with a little leftover.
They are available from https://www.dartagnan.com/ where at first glance, they appear pricey, $14.99 each + shipping. However, D’Artagnan has great sales. Sometimes 40% off. Or sometimes it is free freight. Sign up for their newsletter. Combine orders with friends. You can make it work. I have many favorites.
This duck breast is delicious all by itself….just like that steak I mentioned earlier. But if you want a sauce, I like a gastrique. They have a sweet/sour flavor that can be changed in an instant. Recently I added orange zest and a few diced oranges to the final cooking. That was a bit too predictable for me and I would go back to the time I slow roasted whole grapes with balsamic until they were shriveled. This roasted grape gastrique is my favorite.The point is, you can be very creative with your flavors with a gastrique. For the basics, I am going to send you over to https://www.seriouseats.com/2010/09/how-to-make-a-gastrique-slideshow.html . This explains everything you will ever need to know. Think fruit and acid.