Arrange the artichokes in a steamer basket set over at least 3 cups of water and steam, covered, until the leaves can be easily removed, about 1 hour. Let cool. About halfway through cooking check the water level and add more, if necessary.
In a small bowl, stir together saffron and the tablespoon of boiling water. Toast the almonds in a small dry skillet over medium-high heat until beginning to brown, about 2 minutes. Remove the almonds and add 1 tablespoon of the oil to the pan. Add onion and cook until beginning to brown, 3 to 5 minutes. Add the garlic and cook until fragrant, about 30 seconds. Transfer to a bowl and let cool. In a food processor, grind the almonds until finely chopped. Add the saffron mixture, onion mixture, yogurt and parsley and puree until smooth. Transfer to a bowl and stir in the lemon juice and remaining 1 tablespoon olive oil. Season, to taste, with salt and pepper. Serve with the artichokes.