For the marinade: finely chop the garlic, rosemary, and thyme. Mix with tomato paste, olive oil, red wine, pepper, and salt to taste.
Finely chop the feta cheese. Butterfly the pork fillet by cutting it lengthwise almost all the way through, leaving one edge intact. Rub the fillet with the marinade inside and out. Stuff the chopped feta cheese inside the pocket. Wrap completely with the bacon slices. Refrigerate for 2-3 hours.
Preheat a charcoal grill to high heat. Sear the pork fillet on direct heat for 8-9 minutes. Move to indirect heat and cook for about 25 minutes with the grill cover closed, turning 2-3 times. The internal temperature should reach 68°C (154°F).
Remove the fillet from the grill and rest under foil for 5 minutes. Cut open and serve immediately.
Serve with potato skewers, vegetable skewers, vegetable parcels, colorful salads, and baguettes.