Add bulgur wheat to a small mixing bowl and pour enough boiling water over the grain to just cover. Let stand for 30 minutes, until needed.
Chop cucumber and pepper, and slice radishes thinly. Add vegetables to a large bowl.
When bulgur wheat has soaked for about 25 minutes, add sunflower seeds and salt to the chopped vegetables and toss.
Blend dressing ingredients together in a food processor or with a blender.
Squeeze excess water, if any, from the bulgur wheat and add to the chopped vegetables.
Pour dressing over all salad ingredients and toss together.
Arrange on a plate. Sprinkle with sumac, parsley and mint leaves.