Directions

1. Preheat the oven to 200ºC (400ºF). Lightly butter a 1.5 L (1-1/2 quart) shallow baking dish and set aside.

2. In a large heavy saucepan over high heat, bring 2.5 cm (1 in) of water to a boil. Add potatoes, onions, and 10 mL (2 tsp) of the salt, return to a boil, reduce the heat to moderate, and boil, covered, 5 minutes. Drain and reserve.

3. In a medium-size saucepan, blend 45 mL (3 tbsp) of the butter with flour, the remaining 2 mL (1/2 tsp) salt, and pepper. Set over moderate heat, and, when bubbly, gradually whisk in half-and-half mixture, then milk, and cook, whisking constantly, until thickened and smooth – 5 to 8 minutes.

4. Layer 1/3 of the potato mixture into the prepared baking dish, sprinkle with 1/2 the pimientos and parsley, and top with 1/3 of the sauce. Repeat layers, then top with remaining potato mixture and sauce.

5. In a small bowl, toss crumbs well with remaining butter and scatter evenly on top of casserole. Bake, uncovered, until browned and bubbling – 30 to 35 minutes.