You've heard of "death by chocolate." This is sort of like that. It's a dessert, or an appetizer, or even an amuse-bouche. Any cracker will do, but the payload is the important part, so err on the side of mild. A saltine is a pretty simple and easy to obtain cracker, but water crackers hold up a little better, and thinly sliced pieces of pan-toasted (in the same manner you make croutons) bread from a baguette is probably the best choice.
Cheese should be something with flavor, and a fairly dry cheese, although it must have some oil. I wouldn't go as dry as parmesan, or romano, but a combination of the two might work if it were ground or in thin (very thin) slices. Gouda is wonderful, but an aged, not smoked or fresh gouda. The various bleu cheeses are a bad idea, although gorgonzola is a good choice. Basically, something with a flavor that can stand up to the next ingredient, which is sort of like the nuclear weapon of the culinary arsenal. We get a cheese stocked locally that has peppadew in it, but is otherwise a traditional jack cheese. I have no idea what a peppadew is, but that link gives you an idea of the other possible characteristic of the cheese: don't be afraid to go down the road of cheese with added ingredients. Improvise. You'll have to.
The third ingredient is a habanero pepper. I get about six crackers per pepper. I slice the pepper thinly, and horizontally (across the middle, rather than from the stem down) so they form a ring that I can place on the cracker. I place cheese atop the pepper (I use Red Savinas because I grow them myself; you may find this entirely intolerable and prefer something more like a scotch bonnet, or if you simply haven't the stones, a jalapeno or poblano).
This is the magic. You then nuke it. Give it fifteen seconds or so in the microwave, and make sure that the cheese and the pepper are still firmly joined — this may require some re-arranging — and then another fifteen. Leave them to cool, because you don't want them to get your hands oily.
Precautions. First, working with habaneros, especially of the Savina or other super-hot strains is best done with gloves. This prevents getting their ... treasures in places you wouldn't expect, like under your fingernails, in your eyes, on other sensitive mucosal surfaces of your body (you would not believe how often you touch such surfaces in a given day if you started keeping track; this is another reason people should wash their hands more and learn how to use hand lotion). Second, good grief, they're spicy. The original recipe is the Leary Biscuit. Basically, by heating the cheese, we create a bit of a solvent, which takes the pepper's oily bits (which is where the spicy stuff is, thankfully), and places it into solution. The cracker serves as a substrate and something to pick it up with (otherwise, really, this would be fondue, right? — not that habanero fondue is a bad idea, really…). As with preparation, take care not to get the cheese and oils on your hands.
In general, they are delicious. It's a terrific dish for a summer day with a nice, solid beer (a very hoppy something or other, or something sweeter like a belgian double bock, or a lambic ale maybe) that can "take the heat," as it were. The cheese means that you get to taste all of the pepper, the pepper means you get to experience the heat for, depending on the pepper, even up to a few hours. It kind of sticks to your lips, which is the fun part. You'll be sitting there an hour later, grinning like a fool, reaching for a beer, thinking, man, were those tasty. But you probably won't want another serving for a while.
Enjoy. I figured I'd write this down and submit it to the vast interwebnal peanut galle(r)y for mass consumption because there's no reason potheads should have sole use of the Leary Biscuit as a vehicle for delivering the goodness of plants.