Preheat oven to 425º. Line a small baking sheet with parchment paper.
Place a metal steamer basket in a large pot with an inch of water. Cover, turn heat to high, and bring water to a boil. Once water is boiling, remove the lid and add broccolini. Replace the lid and steam for 2 minutes, until bright green and just the slightest bit tender. Remove from heat.
Place broccolini in a single layer on the parchment paper. Drizzle with olive oil, garlic chili drizzle, and sprinkle with flaky sea salt. Toss to coat evenly.
Roast broccolini for 7-8 minutes on the middle rack, until beginning to brown. Turn broiler to high and broil, still on the middle rack, for 3 minutes, until edges are crispy brown.