Preheat the oven to 200°C/400°F/gas 6. Peel and finely grate the garlic, finely chop the parsley, stalks and all, then mix both with the soft butter and season with sea salt and black pepper. Use the tip of a sharp knife to slice into the thickest part of each chicken breast and create a pocket. Divide and stuff in the garlic butter, then shape the breasts back into their original form, sealing the butter inside.
Gather up one sheet of filo in waves and wrap around one breast. Repeat, lining up the kievs on a large oiled baking tray. Mix 1 tablespoon of olive oil with 1 teaspoon of red wine vinegar, then lightly brush the filo, reserving the remaining mixture for later. Roast on the bottom of the oven for 25 minutes, or until golden, juicy and cooked through.