Pat the chicken breasts dry with paper towels. Rub 1 tablespoon olive oil evenly over the chicken, then press the spice blend onto all sides so they are well coated.

Cook the chicken

Heat a large cast-iron skillet or heavy sauté pan over medium-high heat until hot. Add 1 tablespoon butter and swirl to coat. Add the chicken and cook 4-5 minutes per side until a dark crust forms and internal temperature reaches 165°F (74°C). Reduce heat slightly if exterior is charring too quickly. Total cook time will be about 8-12 minutes depending on thickness.

Rest and slice

Remove chicken to a cutting board and let rest 5 minutes. Squeeze the lime over the chicken, then slice thinly or shred with two forks. Reserve juices on the cutting board to drizzle on nachos if desired.

Cheddar Cheese Sauce

Make a roux: In a small saucepan set over medium heat melt 2 tablespoons butter. Add 2 tablespoons flour and whisk continuously for 1 minute until slightly toasted and mixture turns a pale golden color.

Add milk: Slowly whisk in 1 cup whole milk, a little at a time, whisking to smooth lumps. Bring to a gentle simmer and cook 2-3 minutes until the sauce thickens and coats the back of a spoon.

Finish the cheese sauce: Reduce heat to low and add 1.5 cups grated sharp cheddar and 2 tablespoons softened cream cheese in small handfuls, stirring until melted and smooth. Whisk in 1/2 teaspoon Dijon mustard, 1/4 teaspoon salt, 1/4 teaspoon black pepper and 1/2 teaspoon hot sauce if using. Taste and adjust seasoning. Keep warm on the lowest heat or transfer to a small insulated container.

Nacho Assembly & Toppings

Preheat oven and prepare tray: Preheat oven to 375°F (190°C). Line a large baking sheet with parchment paper or foil for easy cleanup. Spread 8 cups of tortilla chips in an even layer across the sheet, leaving small gaps so chips don't completely overlap.

Layer chips and toppings: Sprinkle half of the black beans and half of the corn evenly over the chips. Scatter about half of the sliced blackened chicken across the chips. Spoon about half of the cheddar cheese sauce evenly over the chips and chicken. Sprinkle half of the diced tomatoes, half of the diced red onion, and half of the sliced fresh jalapeño. Add a light sprinkle of chopped cilantro and sliced green onions.

Bake to meld: Place the baking sheet in the preheated oven and bake 6-8 minutes until warmed through and cheese sauce is bubbling slightly. Watch carefully so chips do not burn.

Finish and serve: Remove from oven and top with remaining sliced chicken, remaining cheddar sauce (warmed if needed), remaining tomatoes, red onion and jalapeño. Add spoonfuls of sour cream and dollops of avocado or guacamole if using. Garnish with extra cilantro and green onions. Serve immediately with lime wedges on the side for squeezing.