1-First Step: Get the oven and baking dish ready

Preheat your oven to 400°F. Take the 2-quart baking dish and spread the softened butter evenly over the bottom. Do not skimp here. A well-buttered dish adds flavor and helps keep the potatoes from sticking, which is especially important when you are chasing those crispy little edges at the end.

2-Second Step: Slice the potatoes

Scrub the russet potatoes clean and slice them thinly. Then cut the slices into quarters. Thin slices matter because they help the potatoes cook evenly and soak up that creamy sauce. If you have a mandoline, this is its time to shine. If not, a steady hand and a sharp knife work just fine.

Peeling is optional, especially if you use russets with thin skins or Yukon Golds. The skins soften as the dish bakes, and they add a little rustic charm.

3-Third Step: Mix the creamy sauce

In a medium bowl, whisk together the heavy cream, whole milk, flour, minced garlic, salt, and freshly ground black pepper. Keep whisking until the flour is blended in and the mixture looks smooth. This sauce is the heart of the dish, so make sure the seasonings are evenly mixed. You want every layer to taste like it showed up dressed for the occasion.

The sauce should look smooth and pourable, not clumpy. If the flour looks stubborn, whisk a little longer and it will behave.

4-Fourth Step: Build the layers

Layer one-third of the potatoes in the buttered dish. Pour one-third of the cream mixture over the potatoes. Repeat that same pattern two more times, ending with the cream mixture on top. This layering method helps the potatoes cook evenly and lets the sauce settle between the slices.

Try to spread the potatoes out as evenly as you can. No potato pile-ups. Every slice deserves its moment.

5-Fifth Step: Bake covered first

Cover the dish with foil and bake for 30 minutes. This first covered bake traps heat and steam, which helps the potatoes soften without drying out. It is the equivalent of letting the dish take a nice warm nap.

6-Sixth Step: Bake uncovered until golden

Remove the foil and bake uncovered for 20 minutes, or until the potatoes are golden brown and bubbling. At this stage, the top should start looking lightly crisp around the edges, and the sauce should be thick and lively. If you peek in and see bubbling, you are on the right track.

7-Final Step: Add the cheese and finish baking

Sprinkle the freshly grated sharp cheddar cheese evenly over the top. Return the dish to the oven for an additional 3 to 5 minutes, just until the cheese melts and turns bubbly. Then let the dish stand for a few minutes before serving. That short rest helps everything settle so the layers hold together better when you scoop.

Total time is about 1 hour 10 minutes, and the payoff is a bubbling, golden pan of comfort.