Step 1: Prepare the Pickle-Brined Garnish (Optional, but Recommended). Take about half of your reserved chopped green onion tops and place them in a small bowl. Pour the dill pickle brine over them. Let them sit at room temperature while you prepare the rest of the dish. This will give them a subtle pickle flavor.

Step 2: Rinse the Potatoes. Place the diced potatoes in a large bowl of cold water. Drain the water. Rinse the potatoes again in a fresh bowl of cold water. Continue rinsing in fresh water until the potato starch has been removed and the water remains clear, about 3 rinsings. This removes excess starch, which helps to create crispy potatoes.

Step 3: Drain the Potatoes. Drain the potatoes well after the final rinse.

Step 4: Cook the Pancetta (or Bacon). Heat the vegetable oil in a large skillet (preferably cast iron) over medium heat. Add the diced pancetta (or bacon) and cook, stirring occasionally, until crisp, about 5 minutes.

Step 5: Remove Pancetta. Remove the crispy pancetta from the skillet with a slotted spoon and drain on paper towels. Reserve the rendered fat in the skillet.

Step 6: Cook the Potatoes. Increase the heat to medium-high. Add the drained potatoes to the skillet with the reserved pancetta fat. Cook the potatoes in one even layer, without stirring, until they are browned and crusted on the bottom.

Step 7: Continue Cooking Potatoes. Stir the potatoes and spread them in a single layer again. Continue to cook, stirring and spreading occasionally, until the potatoes are golden brown on all sides, about 8 minutes total.

Step 8: Add Butter and Onions. Add the butter and the sliced green onions (the white and lighter green parts) to the skillet with the potatoes. Cook, stirring occasionally, until the onions have softened and sweetened a bit, 3 to 4 minutes.

Step 9: Return Pancetta and Add Kale. Return the cooked pancetta to the skillet. Stir in the chopped baby kale and cook until the kale wilts, about 1-2 minutes.

Step 10: Add Cheese. Add the grated Cheddar cheese to the skillet and cook, stirring briefly, just until the cheese is melted and distributed throughout the hash.

Step 11: Season. Season the hash with salt, black pepper, and a pinch of cayenne pepper (if using). Stir in the chopped parsley.

Step 12: Serve. Serve the Colcannon Hash immediately.

Step 13: Top with Poached Eggs (Optional). If desired, top each serving with a poached egg.

Step 14: Garnish and Enjoy! Garnish with the drained, pickle-brined green onion tops and the reserved, un-brined green onion tops.

Step 15: Make the Optional Dill Pickle Relish (While Potatoes Cook). While the potatoes are cooking, combine all the relish ingredients (finely chopped dill pickles, red onion, fresh dill, pickle juice, Dijon mustard, and black pepper) in a small bowl. Stir well to combine. Serve alongside hash.