Cook the Potatoes

Place the peeled and cubed potatoes in a large pot and cover them with salted water.

Bring to a boil and cook until the potatoes are tender, about 15 minutes. Test by inserting a fork; it should slide in easily.

Drain the potatoes and set aside.

Prepare the Cream Sauce

In a medium saucepan, melt the butter over medium heat until it begins to bubble.

Add the flour to the melted butter, whisking constantly to create a smooth paste (roux). Cook for 1-2 minutes to eliminate the raw flour taste.

Gradually whisk in the milk, continuing to whisk until the sauce thickens and becomes creamy, about 5 minutes. The sauce is ready when it coats the back of a spoon.

Combine Potatoes and Peas

Add the drained potatoes back to the pot and pour the cream sauce over them. Gently fold the mixture together.

Add the peas: If using frozen peas, add them now and cook on low heat for 3-4 minutes until heated through. If using fresh peas, steam them separately until tender, then stir them into the mixture.

Season and Serve

Add salt and pepper to taste, adjusting as needed.

For a final touch, garnish with freshly chopped parsley before serving.