Heat up olive in Dutch oven or other deep pot with a lidAdd garlic, carrot and oregano and cook for a couple of minutes until caramelizedAdd 2 cans of tomato pure and cook for a minuteAdd basil, salt, stir it and coverLet it cook for about 15 minutes on a low heatIn the meantime, if you don't have leftover chicken, heat up butter in a skilletSeason the sliced chicken with salt and pepper and cook it on each side until golden brownBoil large pot of salty water and cook pasta according to instructionsAfter the sauce was cooking for 15 minutes, add â…“ cup of grated parmesan, mix it, cover and cook for another 15 minutesOnce sauce is cooked, blend it either by using handheld blender or in a standing blender in batches until smoothIf using standing blender, place the sauce back into your pot, add butter and let it dissolveThen add cooked chickenAdd pasta (reserving one cup of pasta water) and and sprinkle with remaining 2 tablespoon of parmesan cheeseMix everything well and and sprinkle with some more basilIf the sauce is too thick add some pasta water to thin it out