Chef John's Sausage Rolls

Name: Chef John's Sausage Rolls
Prep time: 30 min
Cook time: 30 min
Total time: 1 h
Cuisine: American
Ingredients: 1 pound ground pork; 2 tablespoons finely minced onion; 1 clove crushed garlic; 1 tablespoon minced fresh sage; 1 tablespoon dry bread crumbs; 1.25 teaspoons kosher salt, or to taste; 0.5 teaspoon freshly ground black pepper; 0.25 teaspoon ground coriander; 0.25 teaspoon dried thyme; 0.125 teaspoon cayenne pepper; 0.125 teaspoon freshly grated nutmeg; 1 egg; 1 teaspoon water; 1 sheet frozen puff pastry, partially thawed; 2 teaspoons Sesame seeds for garnish