2. Consider giving them a head start.
Alternately, for a slightly more reliable (and do-ahead!) method, you can pre-poach sausage. Arrange sausages in a sauté pan, cover with beer or water (or both), bring the whole thing up to a simmer over medium heat and let it cook gently for 6–7 minutes. The sausages should be almost fully cooked at this point, and a couple of minutes on a hot grill (or cast iron pan) should be enough to crisp up the casings, get a touch of smoky flavor, and bring the interior to the desired 140 degrees.