Preheat oven to 425°F. Whisk olive oil, lemon juice, shallots, oregano, parsley and garlic in medium bowl to blend. Season vinaigrette with salt and pepper.
Toss potatoes with 1/2 cup vinaigrette on heavy large rimmed baking sheet. Reserve remaining vinaigrette for serving. Pour chicken stock around potatoes. Sprinkle potatoes with salt and pepper. Roast potatoes until tender and golden brown, turning occasionally, about 45 minutes. Cool completely.
Adapted from Bon Appétit, September 2000, Original recipe from Kokkari, San Francisco, CA