Juice of one lime (2 to 3 tablespoons)
1 medium garlic clove, roughly chopped
3/4 teaspoon fine sea salt
1 large bunch cilantro (about 4 ounces/114 grams), washed well, including stems
Roughly chop cilantro. Combine all ingredients in a blender and blend until smooth, stopping to push cilantro down into the blades as necessary.
Notes:
1. A reasonable extra-virgin olive oil from the supermarket is a good choice. The flavor will definitely come through, so choose something that you like. But there's no need to tote out your fancy unfiltered versions with the perfect level of astringency.
2. Plenty of freshly squeezed lime juice and fine sea salt work in tandem to create just the right balance of flavors. (That said, salt preferences vary a lot from person to person, so if you're sensitive to salt, you can start with less and adjust as you go.)
3. Fresh garlic is essential to bring together the flavors. You can vary the amount to suit your preference.
4. The recipe calls for a generous amount of cilantro. Some varieties have a fairly aggressive flavor while others are positively mellow, so taste yours before buying if possible, and make sure you like its specific flavor profile. You'll use both the leaves and stems in this recipe.
5. Store cilantro sauce in a tightly sealed jar in a nice cold fridge for up to a week. The flavor will mellow a bit, but the generous amount of lime juice will prevent the cilantro from oxidizing too much. I sometimes like to store it with a thin layer of additional olive oil on top to create a seal.
6. Or freeze it in ice cube trays, then transfer to an airtight container, and keep in the freezer for up to a year. That way you can defrost it in small portions if you like.