Au Gratin Potatoes (Print Version)
# Ingredients:
→ Main
01 -
3 tablespoons salted butter
02 -
1 small yellow onion, chopped finely
03 -
4 cloves garlic, minced fresh
04 -
0.25 teaspoon black pepper
05 -
0.25 teaspoon salt
06 -
2 teaspoons thyme leaves, fresh
07 -
2 cups Gruyère cheese, shredded
08 -
50 grams Parmesan cheese, grated
09 -
125 millilitres milk
10 -
2 cups heavy cream
11 -
Chives, chopped fine, to top at the end
12 -
1.1 kilograms russet potatoes
# Instructions:
01 -
In a measuring jug, gently heat milk and cream together in the microwave for 1 minute. Keep it aside for later.
02 -
Use a large pot and melt butter on medium heat. Toss in the finely diced onion and stir often while cooking for 10 minutes. Bring the heat down to medium-low and caramelize the onion for another 10–15 minutes. Add thyme and garlic, and let it cook for 2 minutes.
03 -
Turn off the heat to let the pot cool slightly. Slowly mix the warmed milk and cream into the pot. Bring it to a boil over medium-high heat and then take it off again.
04 -
Add the Gruyère and Parmesan, a little at a time, into the sauce. Stir in between to ensure a smooth melt. Sprinkle in salt and pepper to enhance the flavors.
05 -
Peel the russet potatoes, then use a mandoline slicer or a sharp knife to cut them into 3 mm slices. Try to make the slices uniform for even baking.
06 -
Use a 2.5-litre (or 23x33 cm) oven dish, lightly greased. Lay down one third of the potato slices, then sprinkle with a bit of salt. Pour over one third of the sauce. Repeat layers until everything is used up, ending with the sauce on top.
07 -
Use foil to cover the dish and bake at 175°C (350°F) for an hour in the preheated oven.
08 -
Take off the foil and bake uncovered for another 30 minutes. If you like a crispy top, switch to broil mode at 220°C (425°F) for about 1–2 minutes. Watch closely.
09 -
Out of the oven, let it sit for 5–10 minutes so the sauce thickens up. Finish it off by sprinkling chopped chives on top.
# Notes:
01 -
Russet potatoes pack the starch needed to absorb the cream well and help thicken the dish. Consistent slices ensure equal cooking. Work with safety tools if using a mandoline.
02 -
For the best melt and flavor, freshly grate cheese from a block. Pre-shredded kinds might not work as smoothly.
03 -
Don’t worry if the sauce feels runny right after mixing. It’ll tighten up while you bake and once it settles after being taken off the heat.
04 -
Want to make this ahead? Bake for 45 minutes, let it cool, and refrigerate for up to 48 hours. Before serving, bring it to room temperature (1 hour), bake with foil on at 175°C for 20 minutes, then uncovered for 30 more minutes. Broiling is optional.
05 -
Leftovers keep well in the fridge (use an airtight container) for 5 days. Freezing works too, but note the texture might change.