This chili is gluten-free and delicious. The flavor of espresso complements and enhances the flavor of the beef, giving it an umami-boost. A slow cooker makes this chili come together with ease, simmering away at a low temperature while you're out going about your day.
Heat a large, nonstick skillet over medium-high heat. Add the beef and cook, breaking up with a wooden spoon until browned, about 4 minutes. Transfer to a 4-quart slow cooker.
In the same skillet, heat 1 teaspoon of the olive oil over medium-high heat. Add the onion and cook until browned, for 4-5 minutes. Transfer to the slow cooker and add the bell peppers, tomatoes, beans, broth, espresso, chili powder, and cumin.
Stir well, cover, and cook on low for 8 hours. (Alternatively, cook on high for 4 hours.) Turn off the heat and stir in the remaining olive oil, cane juice, and salt.
Meanwhile, in a small bowl, combine the sour cream and cayenne. Cover and refrigerate until serving. To serve, top the chili with the sour cream mixture and garnish with the scallions.