I am immensely proud of myself for pulling this off, and it was so simple and tastes extremely similar to the original recipe. I wish I'd figured this out sooner bc my spouse has been without salsa for roughly a year now. I served it at a Halloween party and no one could tell that it didn't have onion. My wife is allergic to nearly 400 different things—including garlic, onion, corn, tomato (you know, all the things that go in salsa)

Recipe:
1 Avocado
1 Stalk of celery
6 stalks of cilantro
Lime and lemon juice to taste (key lime is a good alternative)
Kosher salt
Pepper
3 Tomatillos
1/2 Anaheim chili pepper
1 jalapeno
1/3 ish cup of water

I also made her a red salsa that I'll post separately, subbed red bell pepper for tomato and amazingly people couldn't tell, even one of our guests who despises red bell pepper was shocked that she had been happily eating the red salsa thinking it was tomato. 

I'm so happy, I've already made 3 batches of the salsa and Halloween was only a few days ago! This is my new go to recipe, and I don't miss the onion even though I love it. I hope this recipe helps someone with food allergies out there! It's tough having to give up all your favorite foods so hopefully this makes a bit easier for any salsa lovers. 

(Since she is allergic to corn, the tortilla chips are cassava and lime, from the brand Siete who specializes in grain free tortilla chips. They're no where near as good as the real thing, but they're healthier and for my wife have been absolutely life changing)

Note: for other salsas that call for garlic, I've just been ommitting it completely as I have not found a substitute that comes anywhere close. Some have suggested ginger, but my wife is very against this. If anyone can think of anything similar to the garlic in flavor that isn't garlic, please let me know! I'm also looking for something to replace fresh corn. She cannot have cauliflower, tree nuts, wheat, or dairy. I'm open to as many creative suggestions as people have! 

Salsa verde cremosa without onion or garlic for my wife who has severe food allergies!