Sausage Rolls

Name: Sausage Rolls
Ingredients: 3 slices bacon, finely chopped; 1/2 onion, peeled and finely chopped; 1 piece of celery, finely chopped; 1 clove garlic, finely chopped; 1 (14-oz.) package of puff pastry, thawed according to package directions; 1 lb. pork sausage; 2 tbsp. chopped, fresh parsley; 1/2 c. panko bread crumbs; 2 large eggs, divided; 1/4 tsp. salt; 1/4 tsp. ground black pepper; Mustard, for serving