This riff on the Negroni comes from the priceless Vintage Spirits & Forgotten Cocktails by Ted Haigh. The drink is named after Lucien Gaudin, a three time competitor and two time gold medal winning fencer in the 1920-28 Olympics. Not a bad record and a rather tasty namesake drink:
1 oz gin
0.5 oz orange liqueur
0.5 oz Campari
0.5 oz sweet vermouth
Combine all ingredients, stir with ice and strain into a chilled cocktail glass. Garnish with orange peel.
The nose is dominated by the orange liqueur and buttressed by the orange notes of the Campari, with a subtle spiciness. The sip is shockingly sweet for a cocktail dominated by bitter ingredients. It begins with almost syrupy sweetness, again from the one-two punch of orange liqueur and Campari. The sweetness fades as the bitterness comes in, providing a lovely transition towards the back of the mouth. The flavors also transition from strong orange notes near the beginning of the mouth to spice notes from the liqueur, gin, and sweet vermouth. The finish is bitter, but not aggressively so, giving it a nice palate cleansing quality.
This is a drink where the ingredients really matter. Everything is present - there's nowhere to hide if something isn't up to snuff. For instance, I chose to make it with Aviation gin, which might have been a mistake. Looking at the recipe, it appears to be a huge bitter fest, but the orange liqueur really holds its own against the other ingredients. A robust London dry gin might be the more appropriate choice. Further, I'd suggest going for a less sweet liqueur if you can find it, as the Campari also lends some sweetness to the opening portion of the sip, and it can easily cross the line into being cloying. Other than the Campari, there's lot of room for experimentation to find the combination of spirits that works best for you.