Lightened Potato-Caramelized Onion Gratin

Ingredients

• 3 pounds baking potatoes peeled thinly sliced
• 1.3 cups breadcrumbs fresh soft
• 1.5 tablespoons butter 
• 0.3 cup flour all-purpose
• 0.3 cup parsley fresh chopped
• 3  garlic cloves minced
• 0.1 teaspoon ground pepper red
• 8 oz six-cheese blend shredded italian
• 1.5 teaspoons penzey's southwest seasoning dried italian
• 2 teaspoons lemon zest 
• 3.5 cups milk 1% low-fat
• 3 tablespoons parmesan cheese grated
• 1.8 teaspoons salt 
• 2 large onions sweet halved thinly sliced

Equipment

• bowl
• oven
• whisk
• baking pan
• dutch oven

Directions

1. Preheat oven to 37
2. Combine first 4 ingredients in a small bowl.
3. Melt butter in a Dutch oven over medium-high heat; add onion, and cook, stirring often, 15 minutes or until onions are caramel colored; add garlic, and cook 1 minute.
4. Stir in flour, and cook, stirring constantly, 1 minute. Gradually whisk in milk and next 3 ingredients. Cook, whisking often, 8 to 9 minutes or until mixture thickens.
5. Remove from heat; whisk in cheese until melted and smooth.
6. Layer half of potatoes in a lightly greased 13- x 9-inch baking dish; pour 2 cups sauce over potatoes in dish. Repeat layers once.
7. Bake, uncovered, at 375 for 1 hour and 10 minutes or until golden brown and potatoes are fork tender, topping with breadcrumb mixture during last 15 minutes of baking.
8. Remove from oven, and let stand 10 minutes.