Sausage Burgers | 1½ pounds loose pork sausage 4 Kaiser rolls or burger buns, split and toasted 2 tablespoons olive oil 3 bell peppers, assorted colors, seeded and cut into ½” strips (about 1½ lbs.) 1 medium yellow onion, sliced ½” thick 2 tablespoons sherry or red wine vinegar 2 tablespoons honey Kosher salt, freshly ground pepper