Use a sharp knife to chop arugula fine. Do not overdo it because arugula goes bitter quickly.
Add hazelnuts and garlic cloves and chop some more. When everything is finely chopped, move the mixture to a bowl, grate some fresh parmesan cheese on top, and season with salt, ground black pepper and about 1 to 2 dollops of extra virgin olive oil. Yes, you have to use extra virgin. Trust us. The amount depends on the pesto structure. It must be moist, but not too moist. Otherwise, it will drain from the chicken breast all over your grill. If the mixture gets too moist, grate some more parmesan – it absorbs extra oil. Mix well and check the taste.
Butterfly your chicken breasts. Use a generous amount of pesto in between and grill the breasts on medium heat. Season with salt and pepper on both sides after grilling, and let them rest cool on the side while preparing the salad.
Salad Instructions
Leave the Manchego to room temperature for at least 2 hours before making the salad.
Wash and dry the arugula, slice tomatoes in half and place in a bowl. Dice the cheese into small cubes.
Add the cheese, walnuts and some olive oil. Season with salt and pepper and mix well. Serve the salad with chicken breasts (which should now be at about room temperature).¡e
Use a sharp knife to chop pesto ingredients rather than a blender. Arugula (and basil, too) go bitter in the blender.
Extra virgin olive oil is the best for making pesto.
Use a sharp knife to butterfly the breast.
Use a generous amount of pesto inside the chicken breast.
Grill the breasts for about 5 minutes on both sides on medium heat.