Caramelized Onion Pasta Sauce

pasta egg
My absolute favorite thing to do in the kitchen isn’t just to bake or cook, or even eat (gasp!). What I truly love to do is to experiment. Sorry Mom, but I just really love to play with my food.

Because really, creating new recipes is so much fun. It’s a chance to channel your inner mad scientist. When I’m working on a recipe, I tweak one thing, try it again, take notes, tweak another thing, take more notes, cackle victoriously, tweak tweak tweak, eat eat eat. By the end I’m usually covered in butter and ready for a nap, but hopefully I’ve at least learned something new and created something delicious. Experimenting with baking is easier to me because all the ratios of ingredients can only be changed in certain ways, so I have more control over everything.

caramelized onions

My point is, you can be a control freak like me and still have fun playing around with a recipe. And you can be a super precise baker and still cook like a boss.

So. Do you like caramelized onions? Of course you do. Do you like pasta? Is that even a question? This one’s for you, friends.

pasta plate
I got the idea for this sauce when I heard about James Beard’s braised onion sauce  and gave it a try. I found it to be too sweet, and I was underwhelmed because it was just pasta with some onions. I still wanted to taste sweet caramelized onions in every bite, but I wanted to tone it down and bring it together into a more cohesive sauce.

raw onion onions 2 onions 3 onions 4

So I experimented: I caramelized onions then blended them with a perfectly ripe avocado, because I’ve seen how avocado pestos really coat pasta well. The powerful sweetness and flavor of the onions get slightly mellowed by the avocado’s creaminess, but you can only taste the avocado if you know it’s there. Then all you need is a little extra vinegar to cut through all that richness, and bam. Perfection.

onion pureeonion avocado puree

This mixture alone makes for a great dip or sandwich spread, but when thinned out with some starchy pasta water? It becomes this wonderful pasta sauce you won’t be able to stay away from.

pasta pot

Some things to note: caramelizing onions takes time, but minimal effort. Do it. Also, not only is this sauce super easy, it also just so happens to be gluten free (and dairy free if you use only oil), so if served on some gluten free pasta tossed with cherry tomatoes, there are few people in the world who cannot eat this.

pastaCreamy Caramelized Onion Pasta Sauce
by L., inspired by James Beard via Food52
Serves 4-6

12 Tbsp butter (or oil of your choice)
3 Tbsp olive oil, plus more if needed
4 medium yellow onions
1 tsp salt
1 1/2 ripe avocados
1/3 cup + 3 Tbsp red wine vinegar
1 lb pasta of choice
1 cup pasta water reserved
salt and pepper to taste

Optional, for serving:
grated parmesan
cherry tomatoes
eggs, fried

First, chop the onions in half then roughly in 1/2” strips – just make sure they’re evenly sliced for even cooking. In a large thick-bottomed skillet, heat the butter (or oil of your choice) and olive oil on low heat and add the onions and salt, tossing them to coat them evenly. Pour in 1/3 cup red wine vinegar. Cook the onions on low for 45 minutes to an hour, stirring every 5-10 minutes or so. They will cook down a lot and get translucent at first, then begin to brown. If you notice they are browning unevenly or too quickly, add more oil and lower the heat. When they are dark brown, soft and caramelized, you’ve succeeded. Remove them from the heat.

In a large pot, boil 5 quarts of heavily salted water for the pasta, then throw the pasta in. While it’s cooking, throw the warm caramelized onions into a food processor or blender and blend until it looks like jam. Add the avocados and keep blending for about a minute, then add the 3 Tbsp red wine vinegar and a pinch of salt and pepper. It will look muddy brown, and not perfectly smooth. But don’t worry, it tastes way better than it looks.

Before the pasta is ready, scoop out about a cup of its starchy boiling water and blend this into the caramelized onion puree (if it doesn’t fit in your food processor, dump the mixture back into the onion pan and just whisk in the water). When the pasta is al dente, drain it and toss the warm strands quickly with olive oil so they don’t stick together. Return the pasta to the pot – off the heat – with the caramelized onion sauce, and loosely toss it all together with tongs or a couple forks. Add more salt and pepper to taste.

Serve as-is in all its sweet caramelized onion glory, or with halved cherry tomatoes, grated parmesan, and a fried egg if you’re so inclined.

pasta yolk

Leave a Reply