In a mixing bowl, combine lime juice, white vinegar, olive oil, sugar, salt, and black pepper. Whisk until the sugar is dissolved and the dressing is well mixed.
Add the thinly sliced red onions to the bowl and toss to coat evenly with the dressing.
Let the onions marinate in the dressing for at least 10 minutes to soften and absorb the flavors.
Garnish with chopped cilantro before serving. Serve as a side dish or as a topping for tacos, grilled meats, or sandwiches.
Notes
Cebolla Ensalada is a versatile recipe that pairs well with Mexican dishes or as a refreshing addition to salads. Adjust the vinegar and lime juice to your taste preference.