Bring a large pot of salted water to a boil.

Prepare the rapini: Trim about ½ inch from the tough ends of the stems and remove any yellowed leaves. Cut into 2–3 inch pieces.

Blanch the rapini: Cook in the boiling water for 1–2 minutes until bright green and just tender. Drain thoroughly and gently squeeze out excess water.

Heat the skillet: Warm the olive oil in a large pan over medium heat.

Cook the aromatics: Add the sliced garlic and stir constantly for about 30 seconds, until fragrant but not browned. If using, add the red pepper flakes.

Sauté the rapini: Add the blanched rapini to the skillet and cook for 4–5 minutes, stirring occasionally, until tender and lightly caramelized. Season with salt and black pepper.

Finish and serve: Remove from heat, drizzle with fresh lemon juice, toss to combine, and serve warm.