To make pesto: Place basil, two cloves of minced garlic, 2 Tbsp of olive oil and a pinch of salt and pepper in a small bowl, and mix until it forms a paste.
Using a sharp knife, make a lengthwise split on the side of each chicken breast to form a deep pocket. Stuff chicken breasts evenly with pesto, rubbing a little on the outside as well.
Place chicken on a lightly oiled baking pan in oven until cooked through, about 20 minutes. (To grill chicken breast instead, preheat grill to medium-high. Rub chicken with some olive oil and place on grill. Cook for five to six minutes on each side.)
While chicken is cooking, make ragout. To a sauté pan, add 1 Tbsp olive oil, plus onion and remaining garlic. Sauté until onion is translucent. Add tomatoes, asparagus and olives, and continue cooking five minutes.
Add lemon zest, and season to taste with salt and pepper.
Slice chicken breasts into 1/2-in. slices and divide evenly among four plates. Top with vegetable ragout. Garnish with Parmesan cheese and basil before serving.
Per serving: 324 calories, 31 g protein, 17 g fat (3 g saturated fat), 13 g carbohydrates, 3 g fibre, 71 mg cholesterol, 349 mg sodium