Start by heating the olive oil in a large pot over medium heat. Once the oil shimmers, toss in the ground beef. Cook it until it browns completely, breaking it apart with a spatula as it cooks. This shouldn't take more than five to seven minutes.

Once the beef is browned, it’s time to add the chopped onion and minced garlic. Stir them in and let their enticing aromas fill your kitchen. Cook these until the onion turns soft and translucent, about three minutes.

Next, fold in the yellow bell pepper. Stir it gently in with the beef mixture. Let it sauté for an additional three to four minutes. The peppers will bring a satisfying crunch and a sweet note to your chili.

Now, pour in those diced tomatoes along with both the red kidney beans and black beans. Give everything a good stir, ensuring all ingredients are well combined. This is where the chili starts to come to life!

At this stage, add the ancho chile powder, ground cumin, salt, smoked paprika, and ground coriander. Stir well to ensure every scoop gets a burst of these spices. Let everything simmer together for about 15-20 minutes, allowing the flavors to mingle.

Right before you’re ready to serve, stir in the nonfat sour cream. This will give the chili a creamy finish and a touch of richness. Garnish with thinly sliced scallions for a refreshing crunch.