While you start boiling water for the potatoes, begin softening the kale by placing the torn leaves in a large bowl with the lemon juice and kosher salt. Massage the kale vigorously for about 1 minute—this breaks down the tough fibers and makes it tender without cooking. The salt and acid will begin to soften and flavor the kale immediately. Once massaged, stir in the sliced green onions and set the bowl aside to let the flavors meld.

Bring a pot of salted water to a boil. Cut the Yukon Gold potatoes into 1/2-inch cubes (no need to peel them—the skin adds texture and flavor) and add them to the boiling water. Cook for 8-10 minutes until they're fork-tender but not falling apart. I find that keeping the potatoes in smaller pieces helps them cook evenly and allows them to better absorb the dressing. Drain well and let them cool for a few minutes while you prepare the dressing.

In a small bowl, whisk together the grainy mustard, extra virgin olive oil, garlic powder, black pepper, and red pepper flakes. The mustard acts as an emulsifier, helping the oil and seasonings combine smoothly. I prefer to add the pepper flakes here rather than at the end—they'll bloom slightly in the oil and distribute their heat evenly throughout the dressing.

Pour the dressing from Step 3 over the warm potatoes while they're still slightly warm—this allows them to absorb the flavors better. Gently fold the warm potatoes into the kale and green onion mixture from Step 1, being careful not to break up the potatoes. The warmth of the potatoes will slightly soften the kale further while the cool kale will prevent the potatoes from getting mushy. Sprinkle the fresh dill over the top and gently toss to combine. Taste and adjust seasoning if needed. Serve immediately or let it sit for 15-20 minutes to allow the flavors to meld.