Start by slicing and deseeding the jalapenos and chopping up the onion.
Bring a pot of water up to a boil and add in the chopped onion and jalapenos. Take it off heat and let it cool down completely.
Transfer the jalapenos and onion to a blender jar along with the garlic.
Add the lime juice, salt, and oil and blend until you get a smooth, creamy sauce.
Notes
Wear gloves while deseeding the jalapenos. Make sure you remove the white 'rib' on the inside as well- that's the portion that packs in the most amount of heat.
Use less jalapenos if you're worried about the sauce being too spicy, and add some fresh cilantro as well to get that perfect bright green color you're looking for- I used it when I made my jalapeno mayo too!
Make sure the jalapenos you're using are firm, fresh and unblemished. This is super important, especially if you're planning on storing the sauce for later.
Depending on the kind of blender you're using, you may get a smooth consistency, or a slightly coarse, chunky sauce. It tastes delicious either way!
If the sauce seems too runny, add half an avocado into the mix. This will help reduce the heat too! Use the other half to make avocado butter spread or garlic avocado spread.