Colin, I've made Alton Brown's Pressure Cooker Chili recommended by one of our members and it was a really big hit. We love it:
http://www.foodnetwork.com/food/recipes/recipe/0,1977,FOOD_9936_28231,00.html
One of the reasons that it is so good is his homemade chili powder:
http://www.foodnetwork.com/food/recipes/recipe/0,1977,FOOD_9936_28230,00.html
A couple of suggestions:
1) Use a heat diffuster (flame tamer) under the cooker, preferably an aluminum one that is 1 to 2 inches wider than your cooker. The cheap ones with the fold-out handles are too small and don't do a good job, IMO, but are better than nothing.
2) Use about 2/3 of the tortilla chips the first time. I must have used thicker chips and the chili was too thick.
3) Lay the chips on TOP of everything else -- don't stir them in before cooking. You'll get less, if any, sticking on the bottom of the pot.
The next time I make this, I'm thinking of using masa harina or pureed white hominy to thicken the chili a little, instead of the chips. Similar flavor, less fat.
4) This recipe should be easy to convert to a Dutch oven method to cook in the oven if you're not into pressure cooking.
5) Costco's stew beef is far superior to that from any supermarket that I've ever tried, and it is usually trimmed very nicely. I cut it smaller since we prefer our chili in 1/2- to 3/4-inch dice. Others prefer larger chunks. Sometimes you can buy chili-grind (coarse-ground) beef. Regular ground beef is too fine to give any textural interest to chili, IMO. Or you can cut your own from a chuck roast if so inclined.
6) I cook large chunks of meat on high pressure for 25 minutes, 1- to 1 1/2-inch dice for 16 minutes, 1/2-inch dice for about 12-14 minutes, and coarsely ground meat for 8 minutes. Remove from the heat and release pressure naturally, about 10 minutes. A natural pressure release will give you the best meat texture.
Rita