Hard boil your eggs using your favorite method. When your eggs are done cooking, set them aside in an ice bath or the fridge to cool. 4 eggs
Chop the cauliflower into 1 inch pieces. These are pretty large chunks because we don't want it to overcook. 1 head cauliflower
Add 1 cup of water to your Instant Pot, then place a trivet or steamer basket down and put the cauliflower on top of it.
Place the lid on the Instant Pot and turn the pressure valve to Sealing. Turn your time to 2 minutes and press the Manual button. Stay close to the pot because you'll want to quick release the pressure by turning the pressure valve to Venting.
Test the feel of your cauliflower by sticking a fork into a piece. If you feel that it could use some more cooking, go ahead and close the lid and let it sit for another minute or two. There is no way to tell you exactly how long your cauliflower will take, because each pot is different and everyone cuts their pieces slightly different.
Carefully lift the cooked cauliflower out of the pot and drain it using a colander. Rinse the cauliflower in cold water to stop the cooking process. Place the cooked and drained cauliflower in a large mixing bowl.
Chop the cooled eggs, celery, and onion. Ensure that all of your ingredients are cooled. 2 stalks celery, 1/2 red onion
Add the remaining ingredients including Greek yogurt, white vinegar, mustard, and pepper to the bowl. Mash together using a fork or an electric mixer until desired texture is reached. 1 1/2 cups Greek yogurt, 1 tbsp vinegar, 1 tbsp mustard, 1/4 tsp black pepper
Notes
Not overcooking the cauliflower is important for this recipe to have the texture of real potato salad, which is why I recommend cooking it for the lowest amount of time and slowly adding time on. I recommend not using cauliflower rice for this recipe, as it will be too mushy.