Stuffed Smoked Flank Steak with Peppers, Spinach & Mozzarella

Step-by-step instructions.

1. Soften the filling

   Preheat the smoker to 275°F; oak or pecan works well with beef. Heat half the olive oil in a skillet over medium heat. Cook the sliced peppers and optional onion for 5–7 minutes until softened. Add garlic for 30 seconds, then spinach and stir until wilted. Cook off visible liquid, spread on a clean plate, and cool while preparing the steak.

2. Butterfly and flatten

   Pat the steak dry. On a stable board, hold the knife parallel to the board and slice horizontally through the thick side, stopping about ½ inch short of the opposite edge. Open it like a book. Cover with plastic wrap and gently pound to an even ¼–⅜ inch. A butcher can do this step for you. Identify the muscle fibers before adding the filling.

3. Season and fill

   Combine salt, pepper, paprika, and Italian seasoning. Brush the steak with the remaining oil and season both sides. Arrange the opened steak so its muscle fibers run left to right. Spread the cooled, drained vegetables and mozzarella in a thin layer, leaving a 1-inch border. Keep extra filling out of the roll if it will not close comfortably.

4. Roll and tie

   Starting at the edge nearest you, roll away from you into a snug log. The fibers should run along the length of the finished log, so cutting rounds later crosses the grain. Place seam-side down and tie with food-safe cotton twine every 1½–2 inches, snug enough to hold without squeezing out the filling. Cook immediately after assembling.

5. Smoke to temperature

   Set the roll seam-side down on a rack over a rimmed pan in the smoker. Smoke at 275°F, allowing roughly 1½–2½ hours. Start checking at 75 minutes. Insert the probe into the center of the filling and check several central spots with an instant-read thermometer. Continue until the coldest center reads 165°F; check the surrounding meat as well. If the outside darkens early, tent loosely with foil and keep cooking.

6. Rest and slice

   Transfer to a clean board and rest 10 minutes. Snip and remove all twine. Use a sharp knife to cut across the log into ½–¾-inch rounds, keeping each spiral supported as you move it to a platter. Spoon the rested juices over the slices and serve right away.