Take a 10” oven-safe frying pan (cast iron is perfect for this) and melt the butter in it over medium heat on top of the stove.
Mix together the milk, eggs, half the melted butter (leave the rest in the pan), salt and flour, in a blender if you have it, but otherwise just in a bowl with a whisk well until the batter is smooth and no lumps of flour remain. Whisk in the chives to the finished batter.
Place the frying pan with half the melted butter into a cold oven and then preheat the oven to 425 degrees.
Once the oven has come to temperature, carefully remove the pan from the oven, and pour the batter into the pan over the melted butter, and sprinkle the cheese over top. Place the pan back in the oven.
While the Dutch Baby is baking, prepare the salad topping. Place the kale in a small bowl and add the olive oil. Season with salt and pepper and massage the olive oil well into the kale. Add the tomatoes and parsley and toss well to coat. Set aside.
Bake for 15 minutes, until the pancake is puffed and golden around the edges.
Sprinkle the salad over the top of the finished Dutch Baby, then cut it into wedges to serve with a few drops of balsamic reduction on top if you wish.