sweet potatoes with pecans and goat cheese

INGREDIENTS

• 1 1/2 pounds sweet potato, scrubbed, unpeeled, in 3/4- to 1-inch coins
• 4 tablespoons olive oil, divided
• 1/4 cup toasted and cooled pecan halves
• 2 tiny or 1 small shallot
• 2 stalks celery
• 2 tablespoons flat-leaf parsley
• 1 tablespoon dried cranberries or cherries (optional)
• 2 ounces firmish goat cheese
• Salt and freshly ground black pepper
• 2 teaspoons red wine vinegar
• 1/2 teaspoon smooth Dijon mustard