Start by roasting your red bell pepper until the skin is charred and blistered. You can do this under the broiler, on a grill, or directly over a gas flame. Once charred, place the pepper in a bowl covered with plastic wrap to steam, then peel off the skin. Chop the pepper into bite-sized pieces and set aside.
Bring a large pot of salted water to a boil. Add the elbow macaroni and cook according to package instructions until al dente. Drain the pasta and set aside.
Heat the olive oil in a large skillet over medium-high heat. Season the steak pieces with salt and pepper. Add them to the pan in a single layer and cook for about 2-3 minutes per side until browned but still juicy inside. Remove the steak from the pan and set aside.
In a medium saucepan, melt the butter over medium heat. Once melted, whisk in the flour and stir constantly for 1-2 minutes to form a roux. Slowly pour in the milk, whisking to avoid lumps. Add garlic powder and onion powder. Cook, stirring frequently, until the sauce thickens and coats the back of a spoon.
Lower the heat and stir in the shredded gouda cheese until melted and smooth.
Add the cooked pasta, seared steak, and roasted red pepper pieces into the cheese sauce. Stir gently until everything is evenly coated and heated through.
Scoop the mac into bowls or plates and serve immediately. This dish is perfect on its own or paired with a crisp side salad.