1-First, slice the Kielbasa into ¼-inch slices without cutting all the way through by placing it between two chopsticks or skewers. Then, cut the sausage crosswise into 1-inch bite-sized pieces, approximately 3 rings per piece, totaling about 40 bites for both rings. Place the bites in a large bowl or baking sheet to set them aside.

2-Next, in a small bowl, combine the mustard, apple cider vinegar, brown sugar, and Worcestershire sauce. Divide this sauce mixture into two bowls for easy use. Add mayonnaise to the first bowl to make a creamy dipping sauce; stir well and refrigerate it while you prepare the bites.

3-Pour or brush half of the second bowl of mustard sauce over the Kielbasa bites, ensuring it gets between the cuts for even flavor. Arrange the bites in a single layer in an air fryer basket and cook at 400°F for 7-9 minutes, shaking halfway through to crisp them up.

4-Finishing and Serving: Remove the bites from the air fryer, place them on a platter, and brush or pour the remaining mustard sauce over them for extra taste. Garnish with chopped parsley and serve warm with the mayonnaise-based dipping sauce. If you prefer using an oven, preheat it to 425°F and line a baking sheet with parchment paper, then prepare and arrange the bites as above, baking for 18-20 minutes until browned.