Place halved new potatoes in a pot, cover with cold water, and sprinkle in a pinch of salt. Bring to a boil over medium-high heat.

Cook until the water is boiling, then reduce heat to medium and cook for 10-15 minutes or until potatoes are tender. If using fresh peas, toss them in during the last 2-3 minutes.

Drain the potatoes (and peas if using frozen) and melt unsalted butter in a separate saucepan over medium heat. Stir in the all-purpose flour to create a roux, cooking for 1-2 minutes until bubbly but not browned.

Gradually whisk in the whole milk into the roux, stirring constantly until the mixture thickens, about 4-5 minutes.

Season generously with salt, black pepper, and garlic powder to taste; adjust as needed.

Gently fold the cooked potatoes and sweet peas into the creamy sauce, ensuring they are well coated. Let it simmer together for another 2-3 minutes to meld flavors.

Serve hot, garnished with fresh parsley for extra brightness.