Oat groats are whole grain oats without the husks removed. They make a hearty dish with wonderful texture. I enjoy using sherry vinegar in dishes like this one because of its marvelous tart‐sweet flavor. Look for it in gourmet stores or in natural food stores.
In a medium saucepan over high heat, bring the broth to a boil. Add the salt and oats and bring to a boil again. Reduce the heat to medium‐low and cook, covered, 1 hour or until the broth is absorbed and the oats are tender. This can be done a day ahead of time; cover and refrigerate the cooked oats.
Preheat the oven to 400°F. In a large bowl, combine zucchini, bell peppers, and onion with 1 tablespoon of the oil, celery salt, and pepper. Toss to coat vegetables thoroughly. Place a rack in the middle of the oven. Place vegetables on a 13 x 9‐inch (not nonstick) baking sheet and roast 15 to 25 minutes until vegetables are done, turning occasionally to assure even cooking.
Bring cooked oats to serving temperature. Remove vegetables from oven and combine with hot cooked oats in a large serving bowl. Add the remaining oil, vinegar, oregano, and parsley and toss to coat thoroughly. Add salt and pepper to taste. Serve in the same bowl or on a serving platter. Garnish with a sprig of fresh parsley.