Line a large sieve with cheesecloth, pour in the yogurt and fold over the edges so it is completely covered. Place the sieve over a bowl and put into the fridge for 12 hours. Put the saffron into a small bowl and add about 2 tablespoons boiling water. Let steep for 5 minutes, and then strain it, reserving the saffron. Put the drained yogurt into a bowl, add the steeped saffron, honey and cardamom, and stir well to combine. Pour into individual serving bowls and refrigerate until ready to serve. Sprinkle with toasted almonds and berries just prior to serving.