Zingy, crunchy, and colorful, this popular Mexican condiment complements anything from tacos to grilled meats. The lime acts as a preservative and also mellows out the sharp onion flavor, while the chile adds a welcome touch of heat.
In a large jar, add sliced onions and about 2 teaspoons of salt. Cover and shake well. To the jar, add a splash of olive oil, cover, and shake again. Repeat with a splash of lime juice.
Add a pinch of salt to the sliced habanero, then add to jar. Add remaining olive oil, lime juice, two big pinches of salt, and two big pinches of oregano. Shake one more time to fully combine. Refrigerate for at least 2 hours, but preferably 24, before using. (Store for up to two weeks in lidded jar in refrigerator.)