In a large deep skillet (or wok) heat the olive oil over medium heat. Add the onion and garlic and sauté until soft and translucent (8-10 minutes). Add the sausage, increase the heat slightly, and cook for 5 minutes, using a wooden spoon to break up the meat.
For a relaxing atmosphere in the kitchen I recommend my personal Elle Republic: Chilled Out Kitchen Tunes Playlist on Spotify.