Cauliflower, Leek and Bacon Gratin

Directions

1. Preheat oven to 350°F (180°C). 
2. Butter an 8-inch (2 L) square dish.
3. In a large pot of boiling salted water, cook cauliflower for 5 min. Drain; set aside in bowl.
4. Meanwhile, cook bacon in a large skillet set over medium heat for 5 min or until crispy. Set aside on paper towels. Discard all but 2 tsp (10 mL) fat. 
5. Add leeks to skillet; cook, stirring occasionally, for 5 to 7 min or until very soft and just starting to turn golden. Transfer to bowl with cauliflower; add bacon.
6. Wipe skillet clean. Melt butter in a skillet set over medium heat. Sprinkle with flour; cook, whisking, for 1 min. Gradually whisk in milk. Bring to a boil and reduce heat. Whisk for 3 to 5 min or until smooth and thickened. Whisk in gruyère, parmesan and salt until cheese is melted.
7. Pour over cauliflower mixture, stirring until well coated.
8. Transfer to buttered dish.
9. To make the topping, stir together breadcrumbs, cheese and butter in a small bowl. 
10. Sprinkle over dish. 
11. Bake for about 30 min or until golden on top and heated throughout.