In a bowl, season the flank steak cubes generously with salt, black pepper, and smoked paprika. Allow the meat to marinate briefly while you prepare the garlic butter.
In a large skillet, melt 2 tablespoons of unsalted butter over medium heat. Once melted, add the minced garlic and sauté for 1-2 minutes until aromatic and slightly translucent, being careful not to let it brown. Once ready, remove from the heat and set aside.
With the skillet still on high heat, add the seasoned steak bites to the skillet. Cook for approximately 3-4 minutes, stirring occasionally, until the steak is browned and reaches your desired level of doneness. After cooking, remove from the heat and drizzle the garlic butter over the steak bites, tossing gently to ensure each piece is well coated.
While the steak is cooking, preheat your oven to 375°F (190°C) to prepare for the nachos.
On a large baking sheet or an oven-safe platter, begin layering the nachos. Start with half of the tortilla chips as the base. Evenly sprinkle half of each cheese variety (cheddar and Monterey Jack) over the chips. Top this layer generously with the garlic butter-coated steak bites and any optional jalapeño slices for added spice. Add the remaining tortilla chips on top, followed by the rest of the cheese.
Place the assembled nachos into the preheated oven. Bake for about 10-12 minutes, monitoring closely until the cheese is wonderfully melted and bubbly.
Once the nachos are out of the oven, immediately top them with diced avocado, a generous dollop of sour cream, a sprinkle of fresh cilantro, and a drizzle of lime juice for brightness.
Notes
For an enticing display, serve the nachos on a rustic wooden board or platter.