Place the butter in a sauce pan on medium heat and whisk the butter until the color turns golden brown and the you smell a nutty aroma. Transfer to a metal or glass container and set aside. Set the pan aside.
Bring a pot of salted water to a boil.
Fill a large bowl with 3/4 of water and set aside.
Roughly chop garlic and hazelnuts, then set aside.
Wash and trim the ends of your broccolini.
Blanche the broccolini in the boiling water for 60 seconds. While the broccolini is boiling gather 1 cup of ice and the large bowl filled with water and place is close by in preparation of your ice bath. Once the broccolini has boiled for 60 seconds, pour the ice in the bowl of water and immediately transfer the broccolini in the ice bath to stop the cooking process. Once the broccolini has cooled down, thoroughly dry using paper towels.
Drizzle olive oil in the same pan you used to brown the butter and place on medium. Sear the broccolini on one side, once you flip the broc add your garlic (add additional olive oil as needed). Once the garlic is tender add the hazelnuts and drizzle in the brown butter. Remove the pan from heat, top with flaky salt, the zest of one lemon and a squeeze of lemon juice. Serve and enjoy!