Aguachile is a Mexican dish from Sinaloa, similar to ceviche, with shrimp cured in lime juice and a spicy serrano and cilantro salsa. Great with scallops too!
Place the cleaned shrimp in a shallow bowl or baking dish with 1 cup of lime juice and ½ teaspoon of kosher salt. Mix together to combine and cover. Refrigerate for 30 minutes, stirring halfway through to ensure the shrimp is evenly coated.
Make the salsa marinade by adding the serrano peppers, cilantro, and the remaining ½ cup lime juice to a blender. Blend until smooth.
Pour the marinade through a fine mesh strainer and into the bowl of shrimp. Stir to combine. Place back in the refrigerator and marinate for an additional 30 minutes.
Add the red onion, cucumber, and avocado into the bowl of shrimp and lightly toss to combine. Taste and adjust salt if needed.
Serve aguachiles with tostadas or tortilla chips.
Notes
How to store. Aguachile is best the day you make it. The shrimp keeps curing in the lime the whole time it sits, so it goes from firm to rubbery fast. I wouldn't keep it longer than about 6 hours.
Make it ahead. You can blend the salsa marinade a day in advance and keep it covered in the fridge. Don't start curing the shrimp until about an hour before you're serving.
Adjust the spice level. Use jalapeños instead of serranos if you want it milder, or leave the seeds in for more heat.
Using quality shrimp. You're eating it raw, so this is worth being picky about. Frozen shrimp that's been fully thawed works great too.
Using cooked shrimp. If raw shrimp isn't your thing, use cooked shrimp and cut both marinating times in half. It won't be traditional aguachile, but it'll give you a good idea of how it tastes.