Creamy Au Gratin Potatoes (Print Version)
# Ingredients:
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01 -
1 small yellow onion, finely diced
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3 tablespoons salted butter
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4 cloves fresh garlic, minced
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2 teaspoons fresh thyme leaves
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2 cups heavy cream
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125 millilitres milk
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2 cups Gruyère cheese, shredded
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50 grams Parmesan cheese, grated
09 -
0.25 teaspoon salt
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0.25 teaspoon black pepper
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1.1 kilograms russet potatoes
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Chives, finely chopped, for garnish
# Instructions:
01 -
Combine heavy cream and milk in a measuring jug. Gently warm in the microwave for 1 minute and set aside.
02 -
Melt butter in a large pot over medium heat. Add diced onion and cook for 10 minutes, stirring frequently. Lower the heat to medium-low and continue to cook for an additional 10–15 minutes until onions are lightly caramelized. Stir in minced garlic and fresh thyme; cook for 2 minutes.
03 -
Remove the pot from heat and let it cool briefly. Gradually stir in the warmed cream and milk mixture. Return to medium-high heat, bring just to a boil, then remove from heat.
04 -
Gradually add shredded Gruyère and grated Parmesan cheese to the sauce, stirring after each addition to allow full melting. Season with salt and black pepper.
05 -
Peel russet potatoes and cut into 3 mm thick slices using a mandoline slicer or sharp knife for even results.
06 -
Lightly grease a baking dish (2.5 litres or 23x33 cm). Arrange one third of the potato slices on the bottom and sprinkle with a small pinch of salt. Spoon over one third of the sauce. Repeat layering two more times until all potatoes and sauce are used.
07 -
Cover the baking dish with foil and bake in a preheated oven at 175°C (350°F) for 60 minutes.
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Uncover and bake for an additional 30 minutes. For a golden top, broil at 220°C (425°F) for 1–2 minutes, watching closely to avoid burning.
09 -
Remove from oven and allow to rest for 5–10 minutes for sauce to thicken. Garnish with chopped chives before serving.
# Notes:
01 -
Select russet potatoes for their starch content which thickens the sauce and enhances absorption. Thin, evenly sliced potatoes ensure even cooking. A mandoline slicer produces consistent results but use all available safety guards.
02 -
Freshly grated cheese from a block is recommended for optimal melt and flavour; avoid pre-shredded varieties.
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The sauce will appear thin initially but thickens as it bakes and upon standing.
04 -
To prepare in advance: Assemble and bake for 45 minutes, cool, refrigerate up to 2 days. Before serving, allow to reach room temperature for 1 hour, bake covered at 175°C for 20 minutes, uncover, bake 30 more minutes, and broil if desired.
05 -
Store leftovers in an airtight container in the refrigerator for up to 5 days. Freezing is possible but may affect consistency.