Get out all of your ingredients and get them measured and ready to go!
Slice your potatoes to between ⅛ and ¼ inch thick. Rinse and set aside.
Preheat your oven to 425 degrees.
Melt butter in large pot over medium heat.
Add onion and cook until tender, stirring occasionally, about 5 minutes.
Add garlic, thyme, salt, and pepper. Stir.
Add potatoes, chicken broth and cream.
Cover, reduce heat to medium-low, and simmer until potatoes are almost tender, about 10 minutes.
Au Gratin Potatoes or Potatoes with Cheese
Dump mixture into a bowl, or just use the same pot OFF HEAT, and add cheeses and gently stir until blended. You want the cheese spread evenly throughout the dish.
Transfer mixture to an 8x8 inch baking dish or the equivalent. Press into an even layer.
Sprinkle evenly with cheese of your choice. We always put the cheddar on first and the parmesan on top.
Bake until cream is bubbling around edges and top is golden brown, about 15 minutes.
Broil if necessary to brown the cheese to your liking.
Allow to stand or rest for 10 minutes before serving.
Serve and enjoy!
Ultimately, baking time will depend on how thinly you were able to slice your potatoes so please adjust your cooking time accordingly. Poke your potato dish with a knife or fork and once your potatoes are tender, and the cheese is melted to your liking on top, your dish is ready to eat!