01 - Rinse rice under cold water until water runs clear. Combine rice, water or broth, and a pinch of salt in a saucepan. Bring to a rolling boil, reduce heat to low, cover tightly, and simmer for 15 minutes. Remove from heat and let stand covered for 5 minutes. Fluff with a fork, then stir in lime juice and chopped cilantro. Keep warm until ready to assemble.
02 - Place sliced steak in a large bowl. Drizzle with olive oil and toss to coat evenly. Add chili powder, cumin, garlic powder, smoked paprika, salt, and pepper. Massage spices into meat until each slice is thoroughly coated. Let stand at room temperature while pan heats.
03 - Heat a large skillet or grill pan over medium-high heat until smoking slightly. Arrange steak slices in a single layer without overcrowding. Cook for 2-3 minutes per side, developing a deep brown crust. Cook just until medium-rare to medium. Remove from heat and tent loosely with foil to rest.
04 - Melt butter in a saucepan over medium heat. Whisk in flour and cook for 1 minute, stirring constantly to form a roux. Gradually whisk in milk until fully incorporated and smooth. Continue cooking and stirring for 2-3 minutes until thickened enough to coat the back of a spoon. Reduce heat to low and add shredded cheddar, Monterey Jack, smoked paprika, cayenne, and salt. Stir until cheese is completely melted and sauce is velvety smooth. Remove from heat.
05 - Divide prepared rice evenly among 4 serving bowls. Arrange sliced steak over one side of each bowl. Add black beans, diced tomatoes, corn kernels, and sliced avocado in sections around the steak. Drizzle warm queso sauce generously over the steak and rice. Garnish with fresh cilantro and a lime wedge on the side. Serve immediately while queso is hot and steaming.