Clean the potatoes by gently rubbing them under fresh running water. Bring a large pot to a boil, then fold the potatoes in and cook for 5 minutes.
Drain the potatoes and transfer into a large bowl. Add in 3 tablespoons of extra-virgin olive oil, rosemary, oregano, sea salt and black pepper to taste, and stir to combine all the ingredients.
Heat 1 tablespoon of olive oil in a large skillet over medium heat. Fold the garlic and the seasoned potatoes in and cook, stirring occasionally, for 2-3 minutes.
Brush the chicken breasts with the remaining 1 tablespoon of olive oil, and season with salt and black pepper to taste. Push the potatoes around the edges, place the chicken breasts in the middle.
Sear the chicken breasts for 2 minutes on each side, then cover with a lid and cook for a further 5 minutes, or until the chicken is tender and cooked through. Remove the chicken from the pan and cut into thick slices.
Divide the pan-roasted Italian new potatoes among plates, and serve with the grilled chicken breast and a green salad.