Heat vegetable oil in a large skillet over medium-high heat. Season beef chuck roast cubes with salt and black pepper, then sear until browned on all sides, about 3-4 minutes.

Transfer the browned beef cubes to the crockpot.

In the same skillet, sauté chopped onion and minced garlic for about 3-5 minutes until softened.

Stir in chili powder, ground cumin, smoked paprika, dried oregano, and cayenne pepper. Cook for about 1 minute to toast the spices.

Pour enchilada sauce, beef broth, diced green chiles, and tomato paste into the crockpot. Combine well with the seared beef.

Add drained kidney beans and pinto beans to the crockpot, stirring gently to combine.

Cover and cook on low for 7 to 8 hours or high for 4 hours.

Mix cornstarch with water to form a slurry. Stir slurry into the chili and cook on high for an additional 15 minutes to thicken.

Ladle the chili into bowls and serve warm, optionally with crusty bread or over rice.