Have lived here in Thailand for some years and all this time have searched for the largish savory banana known as "platano" in Latin America and plantain in English.  Everywhere that I searched including this forum and by googling, I came to a dead end and was informed that plantains are not to be found in the country.  Well, just last week I happened to go to the Kasetsart University yearly fair and to my surprise passed by a stall that had a bunch of the plantains hanging in plain sight.  I bought four from him and have already prepared my favorite Colombian soup/"sancocho de gallina" and made some "patacones" which Latinos will understand.  I have failed to understand why the plantains are not more commonly found here given the number of Latinos, Africans and folks from the Caribbean who use them frequently in their cuisines.  The vendor last week told us that he can be found in Chatuchak Market on Weds. and Thurs.  If you're familiar with Chatuchak you will know that on these two days the sellers bring their plants, flowers, trees, etc.  The other shops remain closed until the weekend.  I hope this information will be helpful. I am attaching a photo.  The plantains are actually larger than they look in the picture. Oh, my Thai partner said the vendor called the plantains, "elephant trunk" bananas in Thai or something like that...

Have you been able to find him at CHatuchak?

 

Where exactly is he and what does he look like? If you can, can you post a picture?