You can have jamabalaya using Tony Cachere's Jambalaya dinner mix...no tomatoes, potatoes, or wheat.  Add a sliced up sausage, foil packet of chicken, or freeze dried shrimp and you have a meal.  I believe their Red Beans and Rice are free of both gluten and potato.

Lundberg Farms puts out a variety of risotto products, as well as anything else you can think of with rice in it.

There are many sources for gluten & potato free foods.  A wonderful place is   (You need to Login or Register in Canada.  All of their foods are gluten free, much of them are potato free.

As for a wheat flour substitute, the rice/tapioca/potato blend can be modified by using something like soy.  The potato adds soft bulk to thin out the crunchiness and "sandiness" of the rice flour, soy can do the same thing in potato's stead.

If you have one of those automatic breadmakers, I have a recipe for gluten-free bread (again, using the modified flour substitute noted above.)

Having that triple allergy really thins out your chances of finding pre-packaged solutions.  All I can say is read the labels of a lot of things at the market.  Now that I know your affliction, I will keep you in mind when I shop.

Also, here's a listing of GF companies:     (You need to Login or Register  Again, some may have potato but then again some don't.