Rinse the broccolini and cut off about a quarter of the stem. If the stems are quite thick, cut them in half lengthwise.

Fill a medium saucepan with water and add 1 teaspoon of kosher salt. Bring the water to a boil over high heat.

Meanwhile, fill a large bowl with ice and cold water.

Add the broccolini to the boiling water and bring back to a boil. Boil for 1 1/2 to 2 minutes. Immediately transfer the broccolini to the ice water and immerse. Drain thoroughly.

Heat the oil and butter in a large heavy skillet over medium heat. Cook until the garlic just begins to show some color, about 2 minutes. Add the drained and cooled broccolini and cook, stirring, until hot.

Sprinkle lightly with kosher salt and freshly ground black pepper.