2 tablespoons olive oil
1 1/4 pounds fennel bulbs (thinly sliced, about 5 cups)
3 cloves garlic (crushed)
  Salt and freshly ground black pepper
1 1/4 cups chicken stock (divided)
1/2 cup dry white vermouth
1 teaspoon fennel pollen (optional)
1 1/2 pounds Yukon Gold or Russet potatoes (peeled and thinly sliced 1/8-inch thick, about 4 cups)
3/4 cup grated Parmesan cheese