Soak the bread in the milk. Bring a pan of salted water to the boil, add the kale and boil for 5 minutes. Drain, reserving the water. Place the kale in a food processor with the bread ( reserving the milk), garlic, cheese and walnuts.
Blitz, then stir in 4 tbsps olicve oil. Use a little of the reserved kale water and milk to thin the sauce to the desired consistency, and taste for salt.
Cook the pasta in the reservd kale water for about a minute less than it says on the packet. Drain, reserving a little of the water. Mix with the sauce and add a little reserved water if needed. SErve immediately.