My chili is pretty paleo, so long as you're OK with tomatoes. And no beans - they're just not needed.
Get a big dutch oven going on med-high heat. Throw in a slab of butter or bacon grease. Rough chop a sweet onion and put it in, let it cook down a bit and caramelize a little. Add 1-2lbs of ground beef (grass fed, of course). Let it brown and break it up into small chunks. Be sure to scrape up any browning bits and mix it in.
Prepare the following spices:
About a tablespoon each of: oregano, thyme, dry mustard, coriander, allspice, cinnamon, paprika, cumin. Add more cinnamon and paprika if you like.
About two tablespoons of: chili powder. Or more.
About 4 tablespoons of: cocoa powder (not dutch processed). Or more.
Dump the above all in, mix it up, reduce heat to low.
Add two cans of tomatoes: 1 28oz can of crushed tomatoes, 1 28oz can of diced tomatoes. I prefer Muir Glen fire roasted organic tomatoes.
Simmer for as long as you can stand it.
Here's a picture of the spices & some tomatoes of a batch I made over the holidays for my inlaws:
Wish I would've taken a picture of the finished product but it was gone too quickly :)
(edited: forgot the cumin)