Cook oat groats in boiling water with a generous pinch of salt for 25-30 minutes. Drain and rinse well under cold running water. Allow oats to drain completely before assembling salad.
Prepare the dressing: in a small bowl, whisk together orange juice, vinegar, honey, soy sauce, garlic and orange zest.
In a large bowl, combine drained oats, grated carrot, celery, scallions, almonds and cranberries.
Pour the dressing over the salad and toss to combine. Taste and adjust seasonings, if needed.
Let stand, covered, for one hour to let flavors develop.
Serve at room temperature or chilled.