Brussels Sprout Au Gratin

I love making this recipe for family events.  I have made it just for me by cutting  it in half; it allows me to have two servings.
Ingredients:

1 lbs Brussels sprouts, trimmed of the tough leaves and woody stems and quartered
3 strips bacon, diced
1 cup of sliced leeks
1 Tablespoon all purpose flour
2 teaspoons minced garlic
1/2 cup low sodium chicken broth
1/2 cup heavy cream
1 Tablespoon fresh lemon juice
1/2 cup grated Gruyere or Swiss cheese

Crumb Topping:
1 Tablespoon Olive Oil
1 cup dry bread crumbs
1/4 cup chopped walnuts
1/2 cup grated Gruyere or Swiss cheese
2 teaspoons minced lemon zest
Kosher salt and black pepper to taste

Preheat oven to 350 degrees. Coat a 2-quart casserole dish with nonstick spray.

Blanch the sprouts in a pot of boiling salted water for 5 minutes; drain and set aside.

Saute the bacon in a skillet over medium heat until crisp - use a slotted spoon to remove bacon to a paper towel lined dish. Add the leeks to the skillet; cook over medium heat until softened.

Stir in the flour and garlic, cook for 1 minute.

Stir in the chicken broth, cream and lemon juice; bring to a simmer and cook until thick - about 2 minutes.

Remove mixture from heat; stir in the sprouts, bacon and 1/2 cup Gruyere or Swiss. Transfer the mixture to the prepared baking dish.

Heat olive oil for the crumb topping in a nonstick skillet over medium heat. Stir in the bread crumbs and walnuts; cook until crumbs begin to brown. Remove mixture from heat to a bowl; let cool 5 minutes.

Stir in 1/2 cup Gruyere or Swiss, the lemon zest, salt and pepper.

Top the Brussels Sprouts mixture with bread crumb mixture and bake until crumbs are brown, 25-30 minutes.

Recipe idea source: Cuisine At Home Magazine - December 2009 issue