Whisk together the chicken seasonings in a small bowl. While the chicken is still on the cutting board, pat it dry and sprinkle with seasonings, toss to evenly coat; set aside.: As you mix the chili powder, cumin, salt, smoked paprika, garlic powder, and onion powder, you will notice a warm, earthy aroma that sets the tone for the dish. Patting the chicken dry helps the seasonings cling and promotes better browning when it hits the skillet. When tossing the pieces, you should see an even dusting of spices, not clumps, ensuring each bite is flavorful. A common mistake is leaving excess moisture on the meat, which steam cooks instead of sears; if you skip drying, the chicken may not develop those golden brown edges that add depth. If the seasoning seems faint, resist the urge to add a lot more salt now; you can adjust later after the sauce reduces and flavors concentrate.
Heat 2 tablespoons olive oil in a heavy bottom skillet over medium-high heat until hot and rippling. Add chicken and sear until golden (chicken will not be cooked through); remove to a plate but don't wipe out skillet.: When the oil is shimmering but not smoking, lay the chicken pieces in a single layer and listen for an immediate sizzle, that is the sound of good Maillard color forming. You want deep golden patches on the exposed meat, which translates into richer flavor in the finished dish. Because the pieces are fairly large, they will not be cooked through during this sear, which is intentional, so remove them when they have a nice crust and place them aside to rest briefly. Leaving them in too long risks drying them out, and overcrowding the pan will trap steam and prevent browning. Keep the skillet's fond, those browned bits are flavor gold for the sauce.
Melt butter in olive oil in the skillet. Whisk in flour and cook, stirring constantly for 2 minutes. Reduce heat to low then gradually whisk in chicken broth. Add chicken back to skillet along with black beans and cumin, salt, pepper and cayenne pepper. Bring to a simmer while stirring until thickened.: The butter joining the remaining oil creates a glossy fat base, and adding the flour transforms it into a roux that will thicken the sauce. As you stir for two minutes, the roux will smell slightly nutty, which removes the raw flour flavor. Gradually whisking in the chicken broth prevents lumps and yields a smooth, velvety base; the broth also adds savory depth that complements the spices. When you return the chicken and add the rinsed black beans, the pan will steam and thicken as it comes to a gentle simmer. Watch for a few visual cues: the sauce will coat the back of a spoon and have no graininess. If it gets too thick, stir in a splash more broth. A common pitfall here is rushing the whisking, which leads to lumps, so take your time and keep the heat moderate to avoid scorching the roux.
Remove from heat and stir in green chilies, cheese until melted then sour cream. Stir in desired amount of rice. Add hot sauce and salt to taste if desired. Optional: Top with additional shredded cheese, cover and let melt.: Top with additional shredded cheese, cover and let melt : Taking the pan off direct heat before adding the sour cream prevents it from separating, so this step protects the sauce's silky texture. When you fold in the green chilies , they bring a fresh, vegetal tang that brightens the simmered sauce; the aroma will shift toward a lively, slightly peppery scent. Adding the freshly shredded cheddar cheese will create ribbons of melt that enrich the sauce with savory, tangy pockets; watch as the cheese softens into glossy strands. Stirring in cooked rice lets grains soak up sauce, changing the balance between saucy and hearty, so add it gradually until you reach the desired consistency. Taste and adjust with hot sauce or more salt, keeping in mind that toppings will also add salt and acidity. A typical error is overheating after adding dairy, which can make it grainy, so gentle warming is the key.
Top with desired toppings such as tomatoes, jalapenos, cilantro, avocados, crushed tortilla chips etc.: The finishing touches are where texture and brightness lift the dish. Fresh diced tomatoes or avocados add cool relief, chopped cilantro brings herbal lift, and crushed tortilla chips contribute a playful crunch. If you add raw jalapenos, their sharp pepperiness will cut through the creaminess and enliven each bite. I like offering a selection so diners can tailor heat and freshness. Avoid adding too many wet toppings at once, which can water down the sauce; instead place them on the side for people to choose. Serve immediately while the sauce is warm and the cheese is still melty for the best contrast between creamy interior and crisp toppings.