Thinly slice the potatoes, onion and garlic. Put them in a big bowl and add a generous sprinkling of nutmeg, salt and pepper and a glug of olive oil (about 2-3 tbsp). Gently mix them together with your hands to ensure even distribution. Then pour the mixture into a large, preferably shallow, oven-proof dish.
2 tablespoon olive oil, 1.2 kg all-purpose potatoes, 2 onions, 8 garlic cloves, salt and pepper, ground nutmeg
Pour in enough vegetable stock to come up to just under the top of the potatoes. Press the potatoes down to ensure they are tightly pressed with just enough stock. Top up with more stock if needed. (It will depend on the shape and size of your dish – see notes below). Drizzle a little more olive oil on top and sprinkle some more nutmeg, salt and pepper on top.
500 ml vegetable stock (or up to 1L as needed)
Bake in the oven for 1¼ - 1½ hours at 180°C / 350°F until the potatoes are fully cooked and soft in the middle.
Notes
This is the quick and dirty way to make this dish. If you have more time and want to do it perfectly then layer the ingredients artfully instead.
Test whether the potatoes are cooked by inserting a fork or knife in the middle. If cooked, it will slide in easily without resistance. If it still feels a little firm, pop it back in the oven for a little longer until soft enough.
Casserole dishes vary in shape and size. Scaling up or down the recipe is easy but the amount of stock required is dependent on the particular dish you use. Use the amount given in the ingredients list as a rough guide but go instead by the look. You need to include as much as is necessary to come up to just below the top of the potatoes so that all the potatoes are submerged except the very top which will go brown and crispy.