Preheat the oven to 375 F/ 190 C/ gas mark 5. You will need a medium size baking dish.
Place the artichokes in a large bowl filled with cold water and scrub them clean using a vegetable brush to remove any soil. Rinse well and dry the artichokes with kitchen towel.
In a medium bowl combine the lemon thyme, oil, garlic, seasoning and stir thoroughly. Cut the large artichokes into quarters and smaller ones in half. Place in the bowl with the herb mixture and stir thoroughly to ensure even coating.
Tip into the baking dish and bake for 40-45 minutes, turning once halfway through.
Serve hot or cold, with a bit of parmesan if you wish.
Do not peel the Jerusalem artichokes, only rub with a vegetable scrub.
Herbs that pair well with this vegetable include lemon thyme, regular thyme, parsley, rosemary and dill.
You can prepare the Jerusalem artichokes ahead, coat in the ingredients, cover and refrigerate for a few hours until you are ready to roast them.
Best served immediately. Leftovers can be enjoyed hot or as a cold snack.