Purple potatoes have the same healthful antioxidant phytochemicals (called anthocyanins) that you find in berries. However if you can't find them, substitute Yukon Golds here. To make chipotle puree, empty a can of chipotles in adobo into a mini chopper and process to a smooth sauce.
4 garlic cloves, peeled
1 tsp. plus 1/4 cup olive oil
2 tbsp. light-flavored oil
2 lb. small to medium purple potatoes, unpeeled
1 yellow or red bell pepper, diced
2 medium carrots, thinly sliced
1 large red onion, very thinly sliced
6 scallions, white and pale green parts only, thinly sliced
1/4 cup chopped oil-cured black olives
3 tbsp. coarse-grain mustard (such as Pommery)
3 tbsp. distilled white or white wine vinegar
1 tbsp. chopped fresh thyme leaves
2 tsp. chipotle puree
Salt and freshly ground black pepper
1. Preheat the oven to 350°F. Place garlic on a sheet of foil. Drizzle 1 teaspoon of te olive oil over garlic. Wrap tightly and bake for 15 minutes, or until soft but not mushy. Puree with light-flavored oil.
2. Meanwhile, place potatoes in a large saucepan with cold water to cover; add 1 tablespoon salt. Cover, bring to a boil, and cook until potatoes are cooked through, 12 to 15 minutes. Drain. When cool enough to handle, slice or cut potatoes into small chunks, or coarsely mash them.
3. In a large glass or ceramic bowl, combine bell pepper, carrots, onion, scallions, and olives. Add cut up potatoes.
4. In a small bowl, whisk together mustard, vinegar, thyme, chipotle puree, and 1 1/2 teaspoons of roasted garlic puree. Gradually whisk in remaining 1/4 cup olive oil. Add enough of the dressing to potatoes and vegetables to moisten. Toss well to coat evenly. Season with salt and pepper and add more dressing as needed. Serve at room temperature or refrigerate, covered, up to 2 days.