ceviche

If you can pronounce ceviche (it's seh-vee-chay), you can make it. It’s one of those things that intimidate people but shouldn’t–in reality, it’s just a simple appetizer. An easy entertaining option as it must be prepared at least a couple of hours before eating, well before any company arrives. Ceviche is fresh, a little spicy, and perfect if you are looking to serve something on the lighter side.

Ceviche isn't cooked in the true sense (cooking involves heat, and this isn't heated). After sitting in the acid from the citrus juice—a process called denaturation—the proteins in the fish change in the same as they would if cooked in heat. However, this preparation won't kill bacteria as heat will, so always use the freshest fish as possible.

I still give a glance at page 89 of James Peterson's Fish and Shellfish before I start chopping ingredients. He gives a nice rundown of what any good ceviche must include. His advice:

Improvise- use whatever you find that's fresh and local(ish).
Use at least one herb. This is most often cilantro, but this is such a common food aversion that it's good to occasionally experiment with some other herbs. Flat-leaf Parsley is a good generic option, but I've also used basil when making a more Italian/Mediterranean version.
Hot Chilies. You must include fresh jalapeño or serrano, but take the seeds and pith out to keep it on the mild side, especially if you've got some guests who might not be able to take the heat. I'll frequently chop some jalapeño, including the seeds, to serve on the side, along with a favorite hot sauce.
Onion/Garlic/Shallots. My favorite is red onion and minced garlic.
Acid. Lime juice, but lemon works, too. Especially if it is at a time of year when you can barely wring any juice out of limes, I also add a bit of white wine vinegar and a few tablespoons of extra virgin olive oil. And the vinegary juice from the bottom of the container of pico de gallo you've got in the refrigerator.

serves 6-8

1/2 lb shrimp, peeled and deveined
1 lb freshest finfish (I like snapper, halibut, pompano, tilapia...), cut into 1 inch cubes
Juice of 2 limes
1 tablespoons white wine vinegar
2 1/2 tablespoons extra virgin olive oil
Red onion, 1 cup diced
1 jalapeno, seeded and finely chopped
1 large garlic clove, finely chopped
1/3 cup of your fave pico de gallo
1/4 cup of the juice from the bottom of the pico container
Cilantro, 1/3 of a cup, diced.
2 large ripe avocados, cut into 1 inch dice

First, fill a small saucepan with water and bring to a boil. Submerge the shrimp, cover the pan and turn off the heat. Cook for one minute, then quickly remove, drain and rinse with cold water. Roughly dice and place into a large bowl. Add the rest of the ingredients, minus the avocado,cover and place in the refrigerator. Allow the fish to "cook" for at least 2 hours, or until it loses its translucent appearance. Add the avocado right before serving.

Serve with tortilla chips. If you are trying to keep it low-carb, just eat with a fork, or serve with crudite for scooping.