To make the crispy kale, put the kale into a large bowl and toss with the lemon zest, olive oil, and a little sea salt. Arrange in a single layer on 1 or 2 baking sheets.
Place in a preheated oven, at 400°F, for 15–20 minutes, turning halfway through cooking time, until crunchy and crisp.
Sprinkle with a little more salt or some sesame seeds, if desired.
Meanwhile, put the turkey into a large bowl with the onions, ginger, garlic, lemongrass, chile, and cilantro.
Mix well, then season to taste and stir in the egg.
Use your hands to shape the mixture into 4 large balls, then press them firmly into patty shapes.
Place under a preheated hot broiler and cook for 5 minutes on each side, or until golden and cooked through.
Serve in warm whole-wheat buns with crispy kale on the side.
Eat Yourself Happy by Gill Paul, Hamlyn 2013, Photo Will Heap.