There is a bread service at Sanaa where you choose 3 breads and 3 dips/spreads to go with them. One of the spreads is verrry spicy. I think its pickled garlic or something like that. The server will know if you ask. We love spicy foods, and this is one of the spiciest things I have ever eaten. Our server said that most people don't like it because it's so spicy. We always order more! I highly recommend it. The food at Sanaa is wonerful too - a must do every trip for us. We are eating dinner there our first night on our upcoming trip!
Another vote for Sanaa! Some of the bread accompaniments are very spicy, particularly the red chile sambal and the green mango pickle. There are other spicy main dishes, but the flavors are so wonderful and unique. I'm getting hungry just thinking about it! Definitely worth a trip to Kidani Village.
A third for Sanaa! At two different dinners, I had the Shrimp in green curry/ chicken in red curry and the vegetarian sampler... all were perfectly spicy, hot and flavorful! I paid my compliments to the chef and manager - nearly kissing them with thankfulness, so happy was I to find something at WDW that wasn't watered down - and was told they can customize the heat at Sanaa. If you want it extra spicy-hot, just ask!
When we were there in March we ate at Kuzzina and I had the Fishermans Stew, it was spicy and warm, not hot, but I'm sure they could increase the heat if you wanted.
Rarely have I ordered anything at Disney that very spicy or hot, might not be a large calling for spicy and hot.
I will confess to carrying packets of cayenne pepper with me to "spice things up". I eat cayenne on pretty much everything except dessert - so if I don't have it on vacation, the food tastes really bland.