Not all Thai food is spicy. In my option this is a huge misconception. Thai good is a mix of sweet, sour, and salty.
There is the spicy: Tom yum, Som tum, Yum wun sen, Pad kee mao
and not spicy:
Crab fried rice, Pad Thai, Baw mee, Kuay teeo (make it as spicy as you want by adding chili peppers), Moo ping, jok...
I've been to Thai restaurants in Southern California that were every bit as good as places here in Thailand and I've been to one place in particular in South Florida that was absolutely terrible. In fact, it was so Americanized I didn't want to comment on the quality of the food.
FOR THE RECORD: If you have not been to Thailand to eat street food, to eat authentic Thai 5-star restaurants AND to eat Thai-food buffet in Thailand, then you don't know what you're missing.
T/hat was for the nay-sayers. LOL I'm adamant about this. LOL
Definitely.
BTW - Thais definitely use onions and tomatoes. I eat Thai food every single day and some of my favorite dishes are Kai jeeo moo sap (Omelete with ground pork - often with onion), Red Onion omelet, Yum wun sen (seafood salad with glass noodles - spicy)...
Both of the below dishes are not spicy
Red onion omelet:
Crispy fried pork belly over rice (with egg):