Costco and roasted vegetable soup — Les Petites Gourmettes

Ingredients

• 1 large onion, peeled and coarsely chopped
• 1 pound asparagus
• 1 pound green beans
• 6 woody sprigs of thyme
• 4 large garlic cloves, unpeeled
• 2 tablespoons olive oil
• Salt and freshly ground black pepper
• 4 cups chicken stock or vegetable broth
• 3 tablespoons minced fresh parsley
• 1 small garlic clove, peeled and finely minced
• 1 tablespoon freshly grated orange zest
• 1 tablespoon freshly grated lemon zest
• Pinch of each: salt and freshly ground black pepper