A sandwich. You could try different bread, or even toast it. A new cheese, a different meat. Spinach rather than lettuce. Avocado in place of mayonnaise. An undigested piece of potato. No, wait not that last one. Anyway, change what you will a sandwich is still a sandwich and is still recognisably so. Much like Rowen's call for Manhattans there are drinks which when altered still retain their identity. This is what I first thought of as a forgiving cocktail. I've mentioned one such drink before but today we'll be seasonally appropriate and be bitter and stirred.
0.75-1 oz whisky
0.75-1 oz brandy
0.75-1 oz vermouth
0.5 tsp - 1 tbsp benedictine
1-2 dashes Angostura bitters
1-2 dahses Peychaud's bitters
citrus twist, peel, or slice (omit if desired)
Choose a desired volume and maintain a 1:1:1 ratio for the first three ingredients. Stir, or shake. Strain, or not. Up or down. Rocks or neat. Garnish or not.
I've discovered recently that it is canonical to shake a Vieux Carré. So here is a drink that could be averaged much like that chocolate chip cookie recipe that made the rounds a few years ago. If you google the Vieux Carré you'll find disagreement about measurements, methods, and garnish but agreement about the ratio and that it's an excellent drink. My recent experiments with yellow Chartreuse VEP in place of Bénédictine didn't offer any marked improvement or intrigue but my variation on one of Erik's variations did. Give it a go!
Vieux Carré (Variation à Dagreb)
1 oz Ballantine's blended scotch
1 oz Pâpidoux calvados
1 oz Cinzano sweet Vermouth
0.75 barspoon Bénédictine
2 dashes Angostura bitters
2 dashes Peychaud's bitters
Stir vigouroulsy amongst whole and cracked ice. Sieve into a chilled coupe. Garnish with peel of oro blanco.