In a small bowl, combine the olive oil, lemon juice, lemon zest, minced garlic, sea salt, and freshly cracked pepper to taste. Whisk together until well combined. Set aside to allow flavors to mingle.
Wash and trim the broccolini, then steam it in a steamer inside a large pot of boiling water for 5 minutes, or until it is crisp-tender.
Drizzle the well-whisked dressing over the broccolini, then toss until coated evenly.