Cook the linguine: Boil a large pot of salted water and cook the linguine until al dente. Reserve 1/2 cup of pasta water, then drain and set aside.
Sauté the peppers: In a large skillet, heat 1 tablespoon of olive oil over medium heat. Add the sliced bell peppers and cook for about 5–7 minutes until they're tender and slightly caramelized. Remove them from the skillet and set aside.
Sear the steak: Season the steak bites with salt, black pepper, garlic powder, and smoked paprika. In the same skillet, add another tablespoon of olive oil and sear the steak for about 3–5 minutes until nicely browned. Remove from the skillet and set aside.
Make the parmesan cream sauce: Lower the heat and add the butter to the skillet. Once melted, add the minced garlic and sauté for about 1 minute until fragrant. Pour in the heavy cream and milk, and let it simmer for 3–4 minutes.
Add the cheese: Stir in the parmesan cheese until it melts into a creamy sauce. Adjust the seasoning to your taste.
Bring it all together: Toss the cooked linguine and sautéed peppers in the skillet, coating them in the sauce. Add the seared steak back in, mixing everything well. If the sauce is too thick, add some of the reserved pasta water to achieve the desired creaminess.
Garnish and serve: Top your dish with some minced parsley, a sprinkle of red pepper flakes, and extra parmesan if you like. Serve warm and enjoy!