Bring a large pot of salted water to a boil. Add linguine and cook according to package instructions until al dente, about 9-11 minutes. Drain and set aside.
Pat the steak cubes dry with paper towels. Season evenly with salt and black pepper.
Heat olive oil in a large skillet over medium-high heat until shimmering.
Add the steak bites in a single layer, cooking in batches if necessary to avoid overcrowding. Sear for 2-3 minutes without moving, then flip and cook for another 2-3 minutes until browned and cooked to desired doneness. Remove steak bites from the skillet and set aside.
Reduce heat to medium. Add 2 tablespoons of butter to the same skillet. Once melted, add minced garlic and crushed red pepper flakes. Sauté for 1-2 minutes until fragrant, stirring frequently to avoid burning.
Return the steak bites to the skillet and toss to coat in the garlic butter sauce. Cook for an additional 1-2 minutes to reheat the steak and meld flavors.
Add the remaining 2 tablespoons of butter to the skillet and stir until melted and combined with the sauce.
Add the cooked linguine to the skillet and toss gently to combine with the steak bites and garlic butter sauce.
Sprinkle chopped fresh parsley and grated Parmesan cheese over the top. Toss lightly once more.
Divide the garlic butter steak bites with linguine evenly among four plates and serve immediately.