To prepare the artichokes: Pour the lemon juice into a large bowl of water – this is to prevent discolouration of the artichokes. Use disposable gloves when handling the artichokes. Wash the artichokes under cold running water and drain. Snap off all the tough outer artichoke leaves. Continue to snap of leaves around the artichoke until you reach the leaves that are almost completely yellow and feel softer than the outer ones. Cut the artichoke stem to 3cm in length from the base. Trim off the outer skin from around the base of the artichoke and the stem. Cut 2-3 cm off the top of the artichoke. Cut the artichoke in half and use a teaspoon to scoop out and discard the furry choke near the base of the leaves. Cut each artichoke half into 4, then immediately place in the bowl of water with lemon juice. Repeat with the remaining artichokes.
Drain the artichokes.
Melt half of the butter with the extra virgin olive oil in a large, deep-frying pan (or stockpot) over medium heat. Add the whole garlic clove and chopped onion. Cook without browning for 2 minutes or until the onion is soft. Add the artichoke and pour in the wine. Cook, stirring, until all the liquid has been absorbed. Add a ladleful of the hot vegetable stock. Season with salt and pepper to taste. Reduce the heat to low and cook for 10-15 minutes. Add more stock if the liquid evaporates. Discard garlic clove.
Stir in the rice and after 2 minutes add a ladleful of the hot stock, stirring constantly. When the stock has been absorbed, stir in another ladleful. Continue to add ladleful’s of stock, stirring and allowing each ladleful to be absorbed before adding the next until the rice is ‘al dente’ (approximately 15 minutes).
Remove the frying pan (or stockpot) from the heat. Stir in the remaining butter and Parmigiano Reggiano. Serve the Risotto of artichokes with grated Parmigiano Reggiano on top – buon appetito.