Fernet-Branca Amaro Liqueur

Probably the most well known brand of the Italian bitters. A bit of explanation here: a fernet is a type of Italian bitters (amaro), Branca is the brand. Originally created in 1845 by Bernardino Branca.
The world’s leading Amaro brand, this gold-medal winning spirit is a complex mix of 27 herbs & botanicals including mint, ginger, rhubarb, saffron, chamomile made from an unchanged 175 year old family recipe, known to one person in the world. The first sip reveals a minty bitterness that opens up into complex spice with a rich finish with the second and third sips.