Cheeseburger Casserole

Name: Cheeseburger Casserole
Ingredients: 1 tbsp. extra-virgin olive oil; 1/2 large white onion, finely diced; 2 lb. ground beef; Kosher salt; Freshly ground black pepper; 2 tbsp. tomato paste; 3 tbsp. pickle relish; 2 tbsp. Worcestershire sauce; 1 tbsp. yellow mustard; 3 c. shredded cheddar; 1 (8-oz.) can refrigerated crescent rolls; 1 large egg, beaten; 1 tbsp. sesame seeds; Shredded lettuce, for garnish; Diced tomato, for garnish; Pickle slices, for garnish; Diced white onion, for garnish; 1/3 c. mayonnaise; 2 tbsp. ketchup; 2 tsp. pickle relish; 1 tsp. apple cider vinegar; 1/4 tsp. garlic powder; 1/4 tsp. onion powder; 1/4 tsp. sweet paprika