Step 1

Preheat oven to 350°F. Spread out coconut flakes on a parchment-lined rimmed baking sheet and toast, undisturbed, until some are golden brown (some will remain white), 5–7 minutes. Let cool.

Step 2

Meanwhile, remove ribs and stems from greens and discard. Cut leaves into 1"-thick strips; set aside.

Step 3

Heat oil in a large skillet over medium. Add garlic and cook, stirring often, until golden brown, about 3 minutes. Add onion, chile, and ginger; season with salt. Cook, stirring often, until onion is softened, about 5 minutes. Add mustard seeds, coriander, and turmeric and cook, stirring to evenly distribute, until fragrant, about 1 minute.

Step 4

Add coconut milk to skillet and bring to a simmer. Add reserved greens a handful at a time, letting each batch wilt slightly before adding more. Cook, tossing occasionally, until greens are tender and mixture looks creamy, 15–18 minutes. Taste and season with more salt if needed.

Step 5

Transfer greens to a platter or large shallow bowl and top with coconut flakes and cilantro.