Ingredients

  • 4 Idaho potatoes, 1 1/2 pounds
  • Salt to taste
  • 1 celeriac or knob celery, 3/4 pound
  • 2 tablespoons lemon juice
  • 1 tablespoon olive oil
  • 1 teaspoon finely minced garlic
  • 4 ripe tomatoes, 1 pound, peeled and cut into 1/2-inch cubes
  • Freshly ground pepper to taste
  • 6 fresh basil leaves
  • 3/4 cup heavy cream
  • 18 teaspoon freshly grated nutmeg
  • Butter for greasing the dish
  • 1/4 pound grated Gruyere cheese

Method

  • Rinse the potatoes and put them in a saucepan with cold water to cover and salt.
  • Bring to a boil and simmer for 15 minutes.
  • They will not be fully cooked.
  • Drain the potatoes and when they are cool enough to handle, peel and cut them into half-inch slices.
  • Pare the celery knob, cut it into quarter-inch slices and put them in a saucepan with water to cover.
  • Add the lemon juice and salt.
  • Bring to a boil and simmer for 10 minutes.
  • Drain and reserve a half cup of the cooking liquid.
  • Preheat the oven to 375 degrees.
  • Heat the oil in a skillet.
  • Add the garlic, tomatoes, salt, pepper and basil leaves.
  • Cook, stirring, for one minute.
  • Add the cream, the reserved half cup of cooking liquid, nutmeg, salt and pepper.
  • Bring to a boil and simmer for two minutes.
  • Grease an oval au gratin dish, measuring 2 1/2 by 8 by 10 inches, with butter.
  • Arrange the potatoes in one layer.
  • Sprinkle half of the grated cheese over the potatoes.
  • Place the celery slices over that.
  • Pour the tomato mixture over all and then the remaining grated cheese.
  • Place on the bottom rack of the oven and bake 40 minutes until nicely browned.