Place potatoes in a medium size saucepan. Cover with water, bring to a boil, and cook until fork tender. Drain and set aside.
Place peas and onions in a saucepan, cover with water and cook for 5 minutes, drain and set aside.
In a large saucepan, or dutch oven, melt the butter. Whisk in the flour, salt and pepper. Cook for 2-3 minutes, whisking constantly. Slowly whisk in the milk and half and half. Cook over a low heat, stirring frequently, until mixture begins to thicken.
Add the potatoes, peas, and onions. Gently fold into the cream mixture until well coated. Simmer over low heat until all ingredients are warm.
Place into a serving dish and garnish top with crumbled bacon.