3 pounds Idaho potatoes, peeled and boiled until tender
6 tablespoons butter, cut into pieces
1/2 cup heavy cream
1/2 cup whole milk
Kosher salt and black pepper
1 1/2 cups cooked chopped kale or cabbage (spinach or other greens would also work)
1 large egg
1 cup all purpose flour
Coconut oil or vegetable oil, for frying
For serving: Greek yogurt or sour cream, smoked salmon