Heat olive oil in a small skillet. Add shallot and cook for 2 minutes. Stir in spinach, 1/2 t. salt, 1/2 t. pepper and 1/8 t. nutmeg. Cook for about 5 minutes, until spinach is fully thawed. Cool.
Meanwhile, combine ground beef, bread crumbs, egg, salt, pepper, garlic powder and Italian seasoning in a large bowl. Mix together until fully incorporated.
Press ground beef mixture into a rectangle on a baking sheet or other easy-to-clean surface.
Layer cheese on top of ground beef, leaving about a 1/2 inch edge all around. Scoop cooled spinach mixture on top.
Roll up jelly-roll style, pressing together tightly as you roll.
Place on a broiler pan or on a cooling rack on top of a baking sheet. Bake at 375 degrees for 30-35 minutes, until fully cooked. Let sit 5 minutes before slicing.