Mist a large nonstick Dutch oven with cooking spray and heat on medium- low. Add sliced onion and cook for 4 minutes, until softened. Add garlic and pepper flakes and cook, stirring, for 30 seconds more, until fragrant. Add milk and broth and increase heat to high. As mixture comes to a boil, add kale, a few handfuls at a time, stirring to combine. Cover and reduce heat to low and cook, stirring occasionally, for 20 minutes, until kale is very tender.
Meanwhile, preheat waffle iron. In a large bowl, combine potato, chopped onion, 1 egg and 2 egg whites. Add curry, ginger and flour and mix. Divide mixture evenly among 4 sections of waffle iron. Close iron and cook for 12 minutes, until waffles are cooked through and crisp on the outside.
Meanwhile, fill a wide, deep sauté pan with water and bring to a boil. Crack 1 egg and carefully drop into water; repeat with remaining 3 eggs in separate spots. Cover, turn off heat, and let cook for 4 minutes. Carefully remove each egg with a slotted spoon. Divide waffles among plates, layer with kale and top with poached eggs.