Step 1: Rinse the broccolini and trim approximately 1/2 inch off the woody ends of the stems. If stalks are very thick, slice them in half lengthwise.
Step 2: Heat the olive oil in a large skillet over medium-high heat. Once the oil is shimmering, add the broccolini to the pan.
Step 3: Add 2 tablespoons of water to the skillet and immediately cover with a tight-fitting lid. Let the broccolini steam for 2 to 3 minutes until it turns bright green and the stems are slightly softened.
Step 4: Remove the lid and allow any remaining water to evaporate. Push the broccolini to the sides of the pan and add the sliced garlic and red pepper flakes to the center.
Step 5: Sauté the garlic for about 1 minute until fragrant but not browned, then toss everything together to coat the broccolini in the garlic oil.
Step 6: Season with salt and pepper. Continue to sauté for another 2-3 minutes until the broccolini starts to develop light charred spots.
Step 7: Remove from heat and squeeze the fresh lemon juice over the top. Serve immediately.