Squeeze the thawed spinach very dry. In a bowl, mix the spinach, feta, sun-dried tomatoes, garlic, ¼ tsp salt, and the pepper until it forms a chunky paste.

Place the turkey skin side down and butterfly it by cutting horizontally almost through, then open it out. Pound to an even ½-inch thickness.

Season the inside with a pinch of salt, then spread the filling evenly, leaving a 1-inch border. Roll the turkey tightly from a short end so the skin ends up on the outside.

Tie the roll with kitchen twine at 1½-inch intervals, trim the ends, and season the outside with the remaining ¾ tsp salt. Rub with the 1 tbsp olive oil.

Preheat the oven to 375°F. Heat a little oil in an ovenproof skillet over medium-high heat. Sear the turkey roll on all sides until golden, about 2 to 3 minutes per side, then move the skillet to the oven. Roast 30 to 40 minutes until the center reaches 160°F.

Let the turkey rest on a cutting board for 10 minutes. Snip off the twine, slice into thick rounds, and spoon any pan juices over the top before serving.