Using a heavy casserole with a cover, saute the onions in the olive oil over low heat, covered, about 20 minutes. Uncover, add garlic and the artichokes, and increase heat. Continue to saute for a few more minutes. Add the chicken broth and salt and pepper, to taste. Bring to a boil and simmer, covered, for 30 minutes. Grind the almonds in a spice grinder and mix with the water. Whisk the mixture into the soup along with with saffron strands and the lemon juice. Reheat, sprinkle parsley on top, and serve.