Add 1 1/2 teaspoons of olive oil to a large skillet set over medium-high heat. When hot, add the sausages and brown on both sides but don't cook them all the way through.  Remove from heat, let them cool, and slice them on the bias. In the same skillet, cook the onions, peppers, and minced garlic in the rendered fat or oil.  Sprinkle with salt and pepper. Return the sausage to pan, cover, reduce heat to medium-low, and simmer for 15 minutes or until it is done. Transfer to a bowl.  Drizzle on white wine vinegar and garnish with fresh rosemary.