- Add the olive oil, soy sauce, red wine, Worcestershire sauce, Dijon mustard, lemon juice, 1 minced garlic clove, Italian seasoning, and pepper to a bowl. Whisk to combine and create the marinade.
- Using a sharp knife, make shallow diagonal cuts about 1 inch apart across the surface of the skirt steak. Place the steak in a large resealable bag and pour in the marinade. Seal the bag, remove as much air as possible, and refrigerate for at least 8 hours or overnight, turning occasionally.
- Preheat oven to 350F. Remove the steak from the marinade and pat dry with paper towels. Discard the remaining marinade.
- On a cutting board, sprinkle the salt over 1 minced garlic clove. Using the flat side of a knife, mash the garlic and salt together to form a paste. Spread the garlic evenly over the top side of the steak.
- Sprinklee the chopped onion and bread crumbs over the garlic paste. Arrange the fresh spinach leaves on top, followed by the shredded swiss cheese, grated parmesan cheese, and chopped sun dried tomatoes.
- Starting at one of the short ends, carefully roll up the steak, enclosing the filling. Secure the roll with kitchen twine or toothpicks at 1-inch intervals. Place the rolled steak seam-side down in a baking dish.
- Bake the steak pinwheels uncovered in the preheated oven for approximately 1 hour. A meat thermometer inserted into the center of the roll should read at least 145F.
- Remove the pinwheels from the oven and let them rest for 5-10 minutes to allow the filling to set. Slice the roll into 1-inch thick pinwheels.
- Serve and enjoy!