Playing Pierogi-wich with Kielbasa

Open-faced sandwiches with caramelized onion mashed potatoes, melted cheese, grilled kielbasa

  • 5 tablespoons butter, divided
  • 2 large onions, chopped
  • 4 cloves garlic. chopped
  • Salt and pepper
  • 2 pounds Idaho or russet potatoes, peeled and cubed
  • 1/3 to 1/2 cup buttermilk
  • 2 tablespoons chopped fresh dill
  • Salt and pepper
  • 1 loaf Italian or peasant-style white bread
  • 3/4 pound Gruyère or Comté cheese
  • 2 pounds kielbasa sausage
  • 1 large bunch fresh radishes
  • Chives
  • Flat-leaf parsley and chives, chopped
  • 4 large deli pickles, garlic or half-sour
  • 3/4 cup brown mustard or grainy Dijon mustard
  • 3 tablespoons sour cream
In a medium skillet over medium heat, melt 3 tablespoons butter. Add onions and garlic, season with salt and pepper, and cook to light caramel in color, 20-25 minutes.  
Meanwhile, cover potatoes with water, bring to boil. Salt water and cook potatoes until tender, drain and return to hot pot to dry potatoes off a bit. Mash potatoes with buttermilk, caramelized onions and dill. Season with salt and pepper to taste. 
Shred cheese on large side of box grater.
Heat a griddle pan over medium high heat. Cut 6-inch lengths of sausage and butterfly them open. Griddle the sausages a few minutes on each side to crisp and brown.
Lightly toast 4 slices of Italian bread on both sides on baking sheet under hot broiler.   
Heat small skillet over medium to medium-high heat.  Wash and quarter the radishes.  Melt 2 tablespoons of butter in pan, when foam subsides add radishes and season with salt. Toss 2-3 minutes, remove from heat and toss with a small handful of chopped chives and parsley.
Halve pickles.
Spread and mound about 1 inch of potatoes on toasted bread.  Top with cheese and place in lower third of oven under hot broiler. Cook to bubbly and lightly brown.
Combine mustard and sour cream.  
Top pierogi-wiches with kielbasa and drizzle with sour cream-mustard sauce. Serve radishes and a pickle alongside.