Creamy Garlic Onion Potato Gratin

Ingredients

• 350 g Potatoes (peeled and sliced 2‑3 mm thick (use a mandoline for uniformity))
• 1 medium Onion (thinly sliced 2‑3 mm)
• 30 g Unsalted butter (room temperature)
• 18 g Garlic, minced (about 3 cloves)
• 5 g All‑purpose flour (approximately ½ tablespoon)
• 100 ml Whole milk (room temperature)
• 20 g Parmesan cheese, grated (about 3 tablespoons)
• 2 g Salt (approximately ½ teaspoon, adjust to taste)
• 100 g Mozzarella cheese, shredded (enough to cover the top; use low‑moisture for best melt)
• 5 g Fresh parsley, chopped (for garnish)

Instructions

1. Slice potatoes

   Peel the potatoes and slice them into uniform 2‑3 mm rounds using a mandoline or sharp knife.

   Time: PT5M

2. Slice onion

   Peel and slice the onion thinly (2‑3 mm).

   Time: PT3M

3. Pre‑cook potatoes in microwave

   Arrange a single layer of potato slices in the microwave‑safe dish, add a splash of water (just enough to create steam), cover loosely, and microwave on high (≈700 W) for 5 minutes until the potatoes are about 80 % done.

   Time: PT5M

4. Sauté garlic

   In a saucepan, melt the butter over low heat. Add the minced garlic and cook gently for 2 minutes, stirring constantly, until fragrant but not browned.

   Time: PT2M

   Temperature: low heat (≈120°C)

5. Make roux

   Sprinkle the flour over the melted butter and garlic, stirring continuously for 1 minute to form a smooth paste.

   Time: PT1M

   Temperature: low heat

6. Create cream sauce

   Gradually whisk in the milk, then add the grated Parmesan and salt. Continue stirring over medium heat for about 2 minutes until the sauce thickens and coats the back of a spoon.

   Time: PT2M

   Temperature: medium heat (≈80°C)

7. Layer the gratin

   In the baking dish, arrange a layer of pre‑cooked potatoes, then a layer of onion slices. Pour a portion of the cream sauce over the layers. Repeat until all ingredients are used, ending with a generous drizzle of sauce on top.

   Time: PT5M

8. First bake

   Place the dish in a pre‑heated oven at 200°C (392°F) and bake for 20 minutes.

   Time: PT20M

   Temperature: 200°C

9. Add mozzarella and finish baking

   Remove the dish, sprinkle the shredded mozzarella evenly over the top, and return to the oven. Bake for an additional 10 minutes, or until the cheese is melted, bubbly, and lightly golden.

   Time: PT10M

   Temperature: 200°C

10. Garnish and serve

    Remove the gratin from the oven, let it rest for 5 minutes, then sprinkle chopped parsley over the surface. Slice and serve while warm.

    Time: PT5M

Nutrition Facts

Calories

260

Protein

10 g

Carbohydrates

30 g

Fat

12 g

Fiber

3 g