Begin by cooking the whole wheat spaghetti according to the package instructions. Make sure to reserve half a cup of the pasta water before draining it.

Season the thinly sliced steak with salt, pepper, garlic powder, and smoked paprika. Heat the olive oil and butter in a large skillet over medium-high heat.

Add the steak in a single layer and sear it for about 3-4 minutes on each side until browned.

Remove the cooked steak from the skillet and set it aside. In the same skillet, add the sliced onion and mushrooms.

Sauté for about 5-7 minutes until the onions are translucent and the mushrooms have released their moisture.

Add the minced garlic to the skillet and cook for an additional minute.

Sprinkle the flour over the veggies and stir well, cooking for another minute.

Gradually pour in the milk and vegetable broth, stirring continuously to prevent lumps from forming.

Allow the sauce to simmer until slightly thickened.

Lower the heat and stir in the grated Parmesan cheese until melted and well incorporated into the sauce.

If it’s too thick, add some of the reserved pasta water to reach your desired consistency.

Return the cooked steak to the skillet and mix well until all ingredients are combined. Add the cooked spaghetti and toss everything together until well coated.

Taste and adjust the seasoning if necessary. Serve immediately, garnishing with extra Parmesan cheese or fresh herbs if desired.