The Best Green Bean Casserole

Ingredients (12)

• 6 slices bacon,
• 1 pound brussel sprouts,
• 2 packages (15 ounces each) cut green beans,
• 8 tablespoons butter,
• 1 large shallot,
• 8 ounces sliced mushrooms
• 6 tablespoons all purpose flour
• 4 cups milk
• 1 1/2 cups shredded parmesan cheese
• Salt and fresh ground black pepper,
• breadcrumbs,
• crispy fried onions,