01 - Rinse and dry the kale thoroughly. Remove tough stems by grasping the leaf at the base and stripping away the green portions. Chop the leaves into bite-sized pieces.
02 - Heat olive oil in a large skillet over medium heat until shimmering.
03 - Add the sliced onion to the hot oil. Sauté for 2–3 minutes, stirring occasionally, until translucent and beginning to soften.
04 - Stir in the minced garlic and grated ginger. Cook for 1 minute, stirring constantly, until fragrant but not browned.
05 - Add the chopped kale to the skillet. Sauté, tossing frequently with tongs or a wooden spoon, for 3–5 minutes until the leaves are wilted and bright green.
06 - Add soy sauce, black pepper, and red pepper flakes if using. Toss well to coat evenly and cook for another 1–2 minutes.
07 - Remove from heat. Squeeze the lemon juice evenly over the kale and toss to combine. Transfer to a serving dish and serve warm.