Using a sharp knife, cut into the fatter side of the breast fillets to make a pocket, taking care not to cut right through the fillet. In a bowl, beat the cheese with the pesto, then divide the mixture evenly between the four pockets, stuffing it well in. Separate the slices of proscuitto and use to wrap round the chicken neatly. Brush an ovenproof dish (of a size that the fillets will fit in in one layer without too much spare room around them) with a little of the olive oil, pop in the parcels then drizzle the remaining oil over the top. Bake in the centre of the oven at 190C for 25 minutes or until cooked through, with no pink showing - the cheesy filling will have partially melted, making a nice sauce. Tip - Try serving each portion with 80g new potatoes and a green leaf side salad with low-calorie salad dressing - adds 80 calories.
