Bring the chicken stock to a boil over high heat.
Clean the artichokes, leaving the tender inner leaves attached to the hearts, and halved. Rub with 1/2 lemon.
Cook artichokes until tender, about 10 minutes.
In a saute pan over low heat, saute onions and garlic together in olive oil. Add rice and toast to harden the outer starch. Add wine and slowly add chicken stock, only adding as much as will evaporate in 1 minute, until rice is cooked and creamy.
When the rice is cooked, remove from heat and allow it to set for a few minutes to absorb any remaining liquid. Just before serving, mix in the artichokes, cheese, chopped parsley, thyme leaves, and salt and pepper, to taste.