Although some people may find broccoli to have a bitter taste, this recipe counters that with the tangy taste of the freshly squeezed lemon juice, and through the use of the sumac spice. The Parmigiano-Reggiano further adds to the complexity of the flavors.
If you do not have sumac you can substitute lemon zest with a bit of additional salt.
Sumac is a very interesting spice. It is made from the wild berries picked from bushes that grow in the Mediterranean and the Middle East. The best Sumac powder comes from the Sicily region in Italy and from Iran. Sumac has a slight lemony and tart taste. Sumac is an important spice in some Mediterranean and Middle Eastern recipes, and goes well with vegetable dishes such as in this Broccoli recipe, with grilled lamb or chicken and with some fish.