Rub the boneless skinless chicken breasts with taco seasoning until evenly coated. Heat a cast iron skillet with olive oil over medium-high heat until hot, then sear the chicken for 5-6 minutes per side until cooked through to 165°F, until the surface looks deeply browned.

Remove the chicken from the skillet and let it rest briefly. Slice the chicken and keep it ready for plating so juices stay in the meat.

In a saucepan over medium heat, melt the butter, then whisk in the all-purpose flour for 1 minute until lightly bubbling and smooth. Gradually add the whole milk while whisking until the mixture is smooth.

Stir in the shredded Mexican cheese blend and Velveeta until melted and glossy. Add the diced tomatoes with green chiles (Rotel), jalapeño, and cumin, then simmer for 3-4 minutes over medium heat until the sauce is smooth and thick, with a slow ribbon consistency.

Plate the sliced chicken and pour the queso cheese sauce generously over the top. Let the orange sauce pool around the chicken so it coats every surface.

Garnish with fresh cilantro and serve with lime wedges on the side for squeezing at the table. Add a squeeze just before eating for bright, fresh flavor.