In a small bowl, whisk all dressing ingredients together; cover and chill until ready to use.
To prepare salad, bring water to boil in medium saucepan; stir in quinoa and simmer, covered, for 10 to 12 minutes. Remove from heat and let stand until all liquid has been absorbed. Fluff with a fork then stir in raisins; let cool. Transfer to a large bowl; add celery, onion, thyme and dressing. Toss to coat well. Cover and chill for at least 1 hour or salad may be prepared to this point and held for 24 hours in refrigerator.
To serve, add walnuts to salad and stir well. Remove thick slice from tops of the tomatoes and scoop out seeds with a small spoon. Arrange on individual salad plates and fill with salad, spooning any extra onto plate around tomatoes.
- 3 Tablespoons extra virgin olive oil
- 3 Tablespoons fresh lemon juice
- 1 Teaspoon sugar
- 1/2 Teaspoon salt
- Freshly ground pepper
- 2 Cups water
- 1 Cup quinoa
- 3/4 Cup California raisins
- 1/3 Cup diced celery
- 1/3 Cup minced red onions
- 2 Tablespoons chopped fresh thyme
- 1/3 Cup chopped toasted walnuts
- 6 large ripe tomatoes