I made this a couple of weeks ago and it was great. It's has a little more prep on the front end than most slow-cooker recipes but it makes a lot. It's from my favorite cookbook, America's Test Kitchen Cookbook.
Slow-Cooker Weeknight Chili
This recipe uses 1/4 c chili powder, which sounds like a lot. However, after 6 to 7 hours in the slow cooker, the heat diminishes. For a spicier chili, increase the cayenne and serve with hot sauce.
2 T vegetable oil
2 onions, chopped medium
1 red bell pepper, stemmed, seeded and chopped medium
1/4 cup chili powder
1 T cumin
1/2 tsp cayenne pepper
6 garlic cloves, minced
2 lbs (85% lean) ground beef
1 (28 oz) can tomato puree
1 (28 oz) can diced tomatoes
2 (15.5 oz) can red kidney beans, rinsed
1) Heat oil in a large Dutch oven over medium heat until shimmering. Add the onion, bell pepper, chili powder, cumin, cayenne, and 1/2 tsp salt. Cook until the vegetables are softened, about 5 minutes. Stir in the garlic and cook for 15 seconds.
2) Add the beef and increase the heat to medium-high. Cook, until no longer pink, about 10 minutes.
3) Stir in the tomato puree and diced tomatoes with their juice, scraping up any browned bits. Bring to a simmer, then pour into the slow cooker.
4) Cover and cook, until the meat is tender, 6 to 7 hours on low or 4 to 5 hours on high. Stir in the beans during the last hour of cooking. Before serving, season with salt and pepper to taste.