Thinly slice the onions and then as thin as you can with a knife or if you have a mandolin slice the potatoes to a thin size, and put them into cold water. Don't worry too much if you cannot get them as thin as mine but make sure the size is consistent so that they cook evenly. Please be so careful with the mandolin they are sharp.

Make sure the potatoes are well covered with cold water, then pick the thyme leaves from the stalks. Get ready to assemble, drizzle the olive oil and butter if using in the bottom of the dish that you are using. I've got a lovely Dutch oven but any baking dish such as for lasagne will do.

Start layering the ingredients, start with some onion scattered then sprinkle some thyme, followed by overlapping slices of potato. Season each time you add the potatoes.

Keep layering until you've used up all onion and potatoes, if it looks like you have more of one than the other just be more generous with that one. When your dish is full of your veg pour over the stock, I've used a homemade chicken stock but you can use any bought stock or bouillon just take care with the salt levels.

This dish classically has a shoulder of lamb sat on top while it slowly braises, I've chosen a piece of pork belly but by all means just cook without if you prefer. Mine cooked for 3 hours at 150c, I separated them at this stage and cooked for another hour.

Basically depending on the size and depth of your dish the timings will vary, mine was very deep so 4 hours at 150c was perfect for the stock to completely absorb into the potatoes but that is for you to work out. This dish is perfect with any roasted meat or as a vegetarian option? Hope you enjoy, see link to video https://www.youtube.com/watch?v=mYqqt3aZ-rE&t=270s