In a small bowl, combine kewpie mayonnaise, heavy cream, minced anchovies, grated garlic, half of the lemon zest, and the juice from half of a lemon. Mix to combine, then taste and add salt and pepper to your liking. Set aside or in the fridge.
In a pan, melt 1 tbsp salted butter and add the panko breadcrumbs. Toast over medium heat until golden, then transfer to a bowl. Stir in a pinch of salt and the remaining half of the lemon zest. Allow to cool to room temperature, then stir in the grated parmesan.
In a large bowl, add the little gem leaves along with the dill fronds and the parsley leaves. Toss to disperse evenly.
Place the little gem lettuce and herb mixture on a plate or platter, then drizzle the anchovy ranch over the top. Alternatively, you can opt to toss the lettuce and herbs with the dressing before plating. Generously sprinkle the toasted panko breadcrumbs across the salad. If you have any remaining sliced chives, garnish with those as well.