In a large skillet over medium-high heat, add the canola oil. Once hot, add the cubed beef chuck. Sprinkle with flour and sauté until the beef is browned on all sides.
In the same skillet, add the minced onion, jalapeño peppers, and garlic. Sauté for about 3-4 minutes until the onions are translucent and fragrant.
Transfer the browned beef and sautéed vegetables to the slow cooker. Add the ground cumin, chopped green chiles, ancho chili powder, crushed red pepper flakes, dried oregano, beef stock, and diced tomatoes with their juice. Stir until everything is well combined.
Cover the slow cooker and set it on low for 6-8 hours or high for 4-5 hours.
Once the cooking time is up, taste the chili and adjust the seasoning if necessary.
Ladle the chili into bowls and top with chopped green onions and a dollop of Greek yogurt. Enjoy it with your favorite cornbread or tortilla chips for a complete meal!