Avocado pickles – a great way to make use of your not-quite-ripe avocados. Not sure what we’re on about? Pickling avocados softens them and makes them a perfect sandwich topping. We love them in a Cubano Sandwich. In a medium non-reactive pot, whisk together the vinegar, water, salt, mustard seeds, sugar, peppercorns, and chile de árbol. Bring the mixture to a simmer over medium heat, stirring until the sugar and salt dissolve, then let it cool to room temperature, about 20 minutes.