Shake all ingredients over ice. Pour into lowball glass and garnish with fresh rosemary sprig.

To make infused liqueur at home, start with a very high quality, clean vodka (Dubay suggests Reyka). Use a high-quality water filter (such as a Brita) to remove any impurities. “The cleaner the base spirit, the cleaner the result,” says Dubay. Add the vodka to a clean glass jar of any size – “you never want your alcohol to touch plastic because alcohol is a corrosive. It will eat away at your plastic cup and put all of those chemicals in your body,” says Dubay – and add the herbs or florals of your choice. Dubay recommends violet or lilac for spring, but any fresh herb, hearty fruit, or vegetable will work. Cover the herb completely with the vodka and infuse for anywhere from one week to a month, depending on how delicate the plant is (i.e. the soft petals of lilacs and violets need far less time to infuse than a hearty herb, since the alcohol can easily penetrate a delicate flower).