Author and culinary arts teacher James Peterson suggests chopping the firm ingredients very finely. Several ingredients that you need to chop finely include chiles, garlic, and onions. For softer ingredients, like tomatoes, you can prepare them coarsely. If you want a chunky textured salsa, use a food processor, but if you want it smooth, use a blender.
Have sterilized pint jars and lids and screw caps ready (they should all be washed in very hot water). Use a canning funnel and ladle hot salsa into jars, leaving a ½-inch head space. Wipe rims clean with a damp cloth and carefully place lid on and screw cap in place. Process in a boiling water bath for 15 minutes, then place upright on counter for 24 hours (see recipe notes for link to USDA Canning Guidelines). You will hear popping sounds as the jars seal. If after 24 hours, any haven't sealed, put in refrigerator to use now.
This recipe is a great starting point to develop your own Mexican salsa recipe. Adjust any or all of the ingredients to suit your tastes. Although this recipe calls for charring the chiles, you can also make it without charring them. Add more chiles for a spicier sauce or reduce the number for a milder version. Substituting jalapeño chiles for the serrano chiles will make a milder salsa too.
As you will notice when we dive a little further into these recipes, Mexican food has a stunning range of somewhat special ingredients. From Masa Harina, the essential ingredient of corn over a wide array of chilies either fresh, dried or ground to Mexican oregano and tomatillos. Some of these may at first glance seem foreign and difficult to come by, but fear not we’ll discuss the individual ingredients as we go and they’ll be easier to come by than you think.