Slice 1/4-inch crosswise cuts along kielbasa without cutting all the way through
In a small bowl, combine Dijon, honey, whole grain mustard, brown sugar, and vinegar. Divide sauce into 2 bowls. Stir mayonnaise into the first bowl until smooth; set aside for dipping sauce. Use the second bowl to glaze the kielbasa.
Preheat the air fryer to 380 degrees F (193 degrees C), and line the fryer basket with a disposable parchment liner (or spray with cooking spray). Cut kielbasa into large links to fit the air fryer basket. Pour or brush mustard sauce over sausage, making sure to get sauce in between slices for maximum flavor.
Place links in a single layer in the basket, and cook until golden brown with crispy edges, 7 to 9 minutes. Check occasionally to avoid overcooking or burning.
Remove sausage links from the fryer, cut into 1-inch pieces, and transfer to a serving platter. Sprinkle with parsley or cilantro, and serve with mustard dipping sauce.
4 servings