How to Make Ultimate Kielbasa and Sauerkraut Sandwiches

Ingredients

• 4 Kielbasa sausages, sliced into rounds (approximately 1 lb/450 g)
• 2 Sweet onions, thinly sliced
• 2 cups Sauerkraut, drained (approximately 300 g)
• 1 cup Gruyere cheese, sliced (approximately 100 g)
• 4 Crusty rolls (such as hoagies or ciabatta)
• ½ cup Whole grain mustard (approximately 120 g)
• ¼ cup Jalapeño jelly (approximately 60 g)