Preheat the oven to 425°F.

Combine crushed garlic, lemon juice, mustard, olive oil, and pepper; mix well.

Cut a lengthwise slit down the center of the tenderloin to within 0.5-inch of the bottom (careful not to cut all the way through).

Open tenderloin so it lies flat. On each half, make another, lengthwise slit down the center to within 0.5-inch of bottom; cover with plastic wrap. Flatten to 0.25-inch thickness with a mallet.

Remove plastic wrap; spread 0.5 of the garlic/Dijon mixture on the inside of the pork. Layer the cheese, spinach, sun dried tomatoes and prosciutto on top, press down gently.

Roll up pork jelly-roll style, starting with a long side. Tie the roast at 1.5-inch to 2-inch intervals with kitchen string.

Season lightly with salt, and remaining garlic/Dijon mixture. Place on a rack in a shallow baking pan.

Bake, uncovered, at 425°F for 25-30 minutes or until a meat thermometer reads 160°. Place under the broiler to brown the top for 5 minutes, then transfer to a serving platter or cutting board.

Let stand 10 minutes before removing string and slicing. Slice in 4 pieces.