Place 1.5 chopped nopales cactus in a pot with 1 garlic clove, ¼ of an onion, and ¼ teaspoon of salt.
Let it cook in its own slime and water for 20 minutes or until they are soft on the inside and outside and have turned into an olive oil color.
Place in a strainer and rinse with cold water, this will help you to stop them from overcooking and get rid of the left mucilaginous texture.
In a container add 1 cup of chopped onion and cover with ½ cup of white or apple vinegar, add ¼ teaspoon of salt, and 1 tablespoon of oregano and let it rest for 3 to 5 minutes.
Add the nopales to the onion, then 2 cups of chopped tomato and 1 jalapeno or serrano in slices.
Mix all together and add salt to taste.
You can add chopped avocado to this salad.
Some people also add ¼ cup of olive oil. I used to do it but it really is not required the vinegar gives all the flavor it needs but I leave you another recipe for a prickled nopales salad recipe here.