1 Lemon
1 Orange
½ cup Olive Oil
4 whole Chiles de Arbol, or ½ teaspoon Crushed Red Pepper Flakes
Peel of 1 Grapefruit
1 pound unfitted Castelvetrano Olives
Halve and thinly slice one half of each lemon and orange, saving the other halves for juicing.
Warm the olive oil in a small pot over medium heat. Add the chiles, lemon and orange slices, and grapefruit peel. Let sizzle a minute or two, then add the olives.
Reduce the heat to the lowest possible setting and let the olive hang out here for anywhere from 10 minutes to 1 hour, stirring every so often. (If your stove's burner is one of those that never quite gets that low, then you might want to max them out around 30 minutes.)
Let the olives cool to room temperature in the pot and then squeeze in the lemon and orange juice from the remaining halves. Serve with citrus peels and all, making sure you have a little dish for the olive pits.