3 (10-oz.) packages frozen chopped spinach, thawed
2 tablespoons unsalted butter
1/2 medium-size yellow onion, finely chopped
3 garlic cloves, minced
4 ounces cream cheese, cut into small pieces and softened
1 cup milk
1 (8-oz.) container sour cream
1/4 cup mayonnaise
1 tablespoon Dijon mustard
1 large egg, lightly beaten
1 (4-oz.) jar diced pimiento, drained and rinsed
2 cups (8 oz.) shredded sharp Cheddar cheese, divided
1 1/2 teaspoons kosher salt
1/2 teaspoon freshly ground black pepper
1/2 cup panko (Japanese breadcrumbs)
2 tablespoons unsalted butter, melted
How to Make It
Preheat oven to 350°. Drain spinach well, pressing between paper towels. Melt 2 Tbsp. butter in a large Dutch oven over medium heat. Add onion, and sauté 5 minutes or until tender. Add garlic, and sauté 1 minute; remove from heat.
Stir cream cheese into onion mixture until melted and well blended. Stir in spinach, milk, and next 3 ingredients. Stir together egg, drained pimiento, and 1 1/2 cups cheese; stir egg mixture into spinach mixture. Spoon mixture into lightly greased (with cooking spray) ramekins or a 2-qt. baking dish; sprinkle with salt and pepper.
Toss together panko, 2 Tbsp. melted butter, and remaining 1/2 cup Cheddar cheese; sprinkle over spinach mixture.
Bake at 350° for 50 minutes or until bubbly and golden.