One of my favorite things to make with cilantro, whether in El Salvador or the US, is chirmol. It's easy, it's tasty, it's healthy and it goes with everything.
3 medium tomatoes, chopped small
1/2 medium onion, chopped small
Juice of 1 large lime
Chopped cilantro to taste
Salt and ground black pepper to taste
Mix up all the ingredients and let it sit for a bit, then enjoy! You can keep it in a sealed container in the fridge for a week.
No matter how big a batch of chirmol you make, you will no doubt have leftover cilantro. A good way to keep it is to let it dry. You can dry it with the stems on or off. I do it on the kitchen counter on a clean cloth and cover it with a second clean cloth. In El Salvador during the rainy season, it takes a while to dry. Once the leaves are crispy, remove them from the stems and put them into a recycled spice jar. I prefer to crush mine right before use.
Dried cilantro is great in chicken soup, beans, rice, salad dressings ... any number of things.