Prepare your broccoli by separating the flowering head from the stalk. Cut the head into large pieces. Use a vegetable peeler or a vegetable knife to remove the outer parts of the stalk and then cut the stalk into 1 inch pieces. Rinse your broccoli well under cool running water.
Bring a pot of water to a boil. This should be a special steamer pot, or a pot which allows you to fit a steamer basket into it, and which can then be covered. Place your broccoli into a steamer basket and steam, over medium heat, for approximately 7 minutes.
Remove the broccoli from the steamer and allow it to cool. When cooled, transfer to a serving platter.
Drizzle the olive oil evenly over the broccoli and then, immediately before serving, squeeze the juice of half a lemon over the broccoli. Alternatively, you can serve the lemon on the side for people to add as they wish. Top with sea salt.