Toast seeds in a frying pan over medium heat for 8 to 10 minutes stirring non-stop, until lightly browned.
Transfer the hot seeds to a bowl and mix well with tahini, stirring well to coat all seeds. Spread seeds out in a single layer and cool to room temperature.
While cooling, combine juice and garlic in a small bowl. Set aside.
Put seeds in food processor or hand held blender along with the juice mixture, soy sauce, celery, minced onion and water; blend until the mixture is fairly fine. Cover and refrigerate if not using the spread within 15 minutes. If spread firms up mix in a tablespoon of water.