Start by finely chopping the red onion, cilantro, serrano pepper, green onion, Roma tomato, and cucumber.
If using parboiled shrimp, chop it into bite-sized pieces. If you prefer raw shrimp, ensure it is fresh and cut it into small pieces.
In a mixing bowl, combine all the chopped ingredients along with the shrimp.
Squeeze fresh lime juice over the mixture, adding salt and hot sauce to taste.
Gently toss everything together until well combined.
Let the ceviche sit for a few minutes to allow the flavors to meld before serving.
