Roasted Leek and Cauliflower Soup with Green Apple Vinaigrette

Name: Roasted Leek and Cauliflower Soup with Green Apple Vinaigrette
Ingredients: For the Green Apple Vinaigrette:; 1 tablespoon extra virgin olive oil; 1 tablespoon plus 1 teaspoon sherry vinegar; 1 teaspoon fish sauce; 1/2 teaspoon Dijon mustard; 1/4 cup Granny Smith apple, diced very small (brunoise, 1/8 inch cubed); For Soup:; 4 large leeks; 3 cups cauliflower florets with stems; 2 tablespoons extra virgin olive oil; 1/2 teaspoon coriander seeds; 1/2 teaspoon cumin seeds; Pinches of kosher salt, plus more to taste; 1/4 cup calvados (apple brandy); 3 cups good chicken stock; 1/2 cup half-and-half