Cut off tough lower portions of the stems, leaving about 3 to 4 inches attached. Slice large pieces in half lengthwise through the entire stem.
In a medium skillet, heat the olive oil over medium high heat. Add the broccolini and cook, stirring occasionally until bright green and starting to brown at the edges, 3 to 4 minutes. Sprinkle with the kosher salt and garlic powder and add 1/4 cup water to the pan. Continue cooking until the stems are bright green and just tender, 2 to 3 minutes.
Stir in the lemon juice and black pepper. Add salt if desired and serve hot.