Serve sausages and cheeses with crackers, grainy mustard, cornichons, apricot jam, and olives.
Prick sausages all over with a fork, and transfer to a skillet (preferably cast iron) over medium heat. Fill skillet with enough water to reach a quarter of the way up sides of sausages. Simmer, covered, until sausages are cooked through and water evaporates, 10 to 15 minutes. (If sausages have cooked through but water has not evaporated, uncover, and continue to cook until water evaporates.)
Continue to cook sausages, turning, until crisp and golden brown all around, about 3 minutes. Serve with cheeses.