Begin by washing all of the vegetables.
Thinly slice (julienne) the purple onion into long slices.
Add purple onion slices to a large bowl where the ceviche will be prepared.
Chop 3 limes in half and squeeze all halves into the onions, mix well.
Now, add 1 tbsp. salt to bowl, mix to combine all ingredients.
Allow onions to marinate with lime juice and salt while preparing other vegetables.
Next, fourth the cherry tomatoes and set aside.
Then, de-stem and roughly chop the cilantro leaves, set aside.
Prepare the heart of palm by draining them from the liquid and slicing them into 1/4 inch circles.
Then, half each into half circles and set aside.