Spicy Buffalo Onion Rings and Blue Cheese Dip

Name: Spicy Buffalo Onion Rings and Blue Cheese Dip
Ingredients: Vegetable oil, for frying; 4 eggs; 5 cups 2 percent milk; 6 cups all-purpose flour; 1 tablespoon baking powder; 1 tablespoon Cajun spice mix (recommended: Paul Prudhomme's); 2 tablespoons cayenne pepper; 1 teaspoon white pepper; 2 teaspoons black pepper; 2 teaspoons dry mustard; 1 2/3 teaspoons salt; 3 extra-large yellow onions; Blue Cheese Dip, recipe follows; 1 carrot, sliced; 1 stalk celery, sliced; 2 cups sour cream; 1 cup buttermilk; 2 cups blue cheese; 1 tablespoon minced serrano chile peppers; 1 tablespoon balsamic vinegar; 1 tablespoon Worcestershire sauce; 1 tablespoon hot sauce; Salt and freshly ground black pepper