Put the garlic in a saucepan and cover with water. Bring slowly to the boil over low-medium heat, then drain. Repeat this process and then slip the skins off each clove and set aside in a bowl.
Refill the saucepan with water and return to the boil over high heat, drop the broad beans into the boiling water for 1 minute only. Immediately drain in a colander and tip into a bowl of ice-cold water. Then double-peel the broad beans. Reserve until needed.
Melt 30 g of the butter in a sauté pan over a medium heat. Once it starts to froth add the artichoke pieces, turnips and peeled garlic and sauté until the artichoke pieces become golden flecked with brown. Add the vegetable stock and peas, then cook, covered, for 5 minutes.
Uncover, scatter over the broad beans and herbs and shake gently to mix; there should be very little liquid remaining in the pan. If it still looks sloppy increase the heat to high and continue to shake the pan. Add the remaining butter to form a small amount of sauce. Taste for seasoning; there probably won’t be any need to add salt. Grind over some black pepper and serve at once.