Basic Guacamole
I think to Canadians, nothing says "Mexican food" louder than guacamole. It is a favorite of (almost) everyone, and how could it not be: the rich, creamy texture of the mashed avocado; the crunchiness of onion, the freshness and acidity of tomato; the vibrant mixture of Mexican flag colors (yes, yes, Italian flag, too).
I think the biggest key to the success of a guacamole is the quality of the avocados. Sure, you won't like soggy tomatoes in your guac, and wilted onions are very disappointing, but less than great avocados really make the guacamole not worth it. In Toronto, you can only get a couple different kinds of avocados, so I would always go for Hass avocados. I like to buy the smaller kind, the kind that come in green plastic nets, because I think their quality is more consistent. I also like to buy avocados while still green and let them ripe at home for about 3 days.
Many restaurants add some acidic agent (like sour cream) to delay the guacamole from turning black. I think this practice is fine for the restaurant industry, where you need to have the guacamole prepared in advanced for the day. However, guacamole is best when freshly made, and adding sour cream takes it to Tex-Mex country. Some restaurants will make it at the table, maybe even letting you choose the amounts of each ingredients.
Ingredients
2 large or 4-5 small ripe avocados
1 medium tomato, skinned and diced
3 tbsp chopped white onion
2 or 3 fresh serrano or 1 fresh jalapeño peppers, finely chopped
1 1/2 tbsp of fresh coriander leaves, roughly chopped
a splash of olive oil
salt, to taste (about 1 tsp)
juice from pickled jalapeño peppers, or lime juice, to taste (optional).
Mash the avocado pulp roughly. Add the salt and taste until you are satisfied with the seasoning. If you're adding pickled jalapeño juice or lime, do the same. Mix in the rest of the ingredients and serve immediately.
Notes
Traditionally, the guacamole is served with one of the avocado pits (cleaned) on top. The lore is that the avocado pit will delay the blackening of the guacamole. While I question the validity of this, except perhaps where the avocado is covered by the pit, it does make a very quaint presentation.Guacamole is often served with corn chips, which are a fun way to eat the guacamole. (Just watch out for double-dippers!) The best is if you make the chips yourself by cutting a corn tortilla into triangles and deep frying the chips. Of course, it's not always possible (and I'm afraid I end up eating a quarter of the chips when frying them--they are irresistible). La Tortillería sells tortilla chips that they fry themselves and are quite good. They call them "Nacho chips." In a pinch, I would use commercial chips, preferably "Garden Fresh."
A better way to make the guacamole, as suggested by Diana Kennedy, is to crush some coriander, onion, the peppers and the salt in a mortar (ideally, a molcajete, or volcanic stone mortar), then add the mashed avocado, listed tomato, onion and coriander. I prefer to do this myself, except I like to add the salt directly to the avocado so I can get the savory level perfectly, and I also prefer to bite into the chopped peppers, so I add them at mixing time.
The way I mash the avocado, which I find efficient and quick, is to cut the avocado in half and remove the pit. Then, with the avocado still in its peel on my left hand, I use a fork on my right hand to "skim the surface" (that is, align the tines of the fork more or less horizontally to the surface of the avocado and take off the top layer). As I "skim", I drop the avocado mash onto the mixing bowl and end up with just the peel.
If I don't have fresh serrano or jalapeño peppers, I will use pickled jalapeños, in which case, I would crush them with the coriander and onion.
Instead of salt, I use Mexican Knorr chicken bouillon. I don't like the Canadian or Chinese Knorr, because it is sweeter, and the flavor is not as good. Mind you, Knorr bouillon has MSG. In Toronto, it is very difficult to find granulated Knorr bouillon, but you can get it in cubes, which is more difficult to measure and use for guacamole.
I like both flavors of pickled jalapeño juice and lime juice, but it's not a good idea to use both, because to get enough flavor leaves the guacamole a bit watery. One good compromise that a Romanian friend of mine suggested was to use lime zest instead of the juice. The flavor is more intense, although not as fresh, and it goes well with the jalepeño juice.
If you don't like coriander, or if you don't have it fresh, you can skip it altogether. However, do not use dried coriander leaves.
When dicing the tomato, make sure you remove the seeds and juice.