Help a Mom: Toddler won't eat fruits, veggies

I got this desperate email from a mom a couple of weeks ago. And she could sure use some help. Do you have any advice?

From Delita:

I am writing you because I am desperate to get my 20-month-old son to eat fruits and vegetables. I have tried various fruits, whether from the can/cup or fresh, and he will not eat them. My son doesn't even like to eat strawberries or bananas! He will put the fruit in his mouth and soon as he bites down, he spits it out. The same goes for vegetables. I have even succumbed to put cheese on the vegetables thinking the cheese will make the veggies more appetizing, but no luck. I have read from various sources to try at least 10 times before giving up on fruits and vegetables but I am looking for ways to disguise them. My son loves mashed potatoes. I have even tried to hide small pieces of vegetables inside. As soon as he tastes the vegetable, he spits it out. I am open to any and all suggestions! Thank you.