We buy the tomatoes on the vine type, still grown in a hothouse but better than loose tomatoes. I hope you like them. I have 5 tomatoes to fix this way tomorrow. :)
This is one of our favorite ways to use the little vine-ripened guys; I think we first found it in a Julia Child book, and then found it modified with cheese (though, we use Parmesan instead of Gruyere):
http://www.foodnetwork.com/recipes/ina-garten/provencal-tomatoes-recipe.html
=JT