Buttermilk Blue Cheese Potatoes Au Gratin

Ingredients

• 7 medium russet potatoes, parboiled, peeled, and thinly sliced
• 2-1/2 tablespoons butter
• 1 clove garlic, crushed
• 2 shallots, minced
• 2 tablespoons all-purpose flour
• 1-1/2 cups milk, at room temperature
• 1 teaspoon white pepper
• 1/4 cup mayonnaise
• 1 teaspoon Dijon-style mustard
• 1/2 teaspoon Worcestershire sauce
• 1/4 cup chopped fresh parsley
• 2 ounces blue cheese, crumbled, divided
• 1 cup buttermilk, at room temperature
• 3 cups sliced mushrooms
• 1 cup grated Monterey Jack cheese
• 1-1/2 cups coarsely crushed potato chips
• 2 cups chopped broccoli
• 1 tablespoon diced pimiento, for garnish