busy mum potato onion tart

 I found this recipe on pinterest as a side dish but we serve it as a tart with salad for a main meal.

It is really yummy.

I have also served it for guests for lunch and they left with the recipe they liked it so much.

It is easy enough for the kids to do.
 I use Desiree potatoes, I buy them by the bagful at my local fruit and veg- they cost me 99c a kilo and I don't need to peel them. 

I have doubled the original recipe, if you don't have as big a family as me feel free to halve it.
If you have not used Gruyere cheese before do not be put off by the smell- it will smell when you grate it and when it is cooking but it tastes divine- believe me!

4 tablespoons butter 12 sprigs thyme, strip the leaves from the stems or other herbs from your garden  B2 made the one pictured and I am not sure what he used as we didn't have any thyme  2 large onion, sliced somewhat thickly ( a tad more than 1/4 inch thick) 1 kg. desiree potatoes, washed and very thinly sliced - I use my v-slicer for this 3 tablespoons olive oil 1 cup grated gruyère  2 cups grated mozzarella sea salt and cracked black pepper Preheat oven to 200° C.  Melt the butter in a 9-10 inch ovenproof frying pan (cast iron is great) over medium heat.  Add the thyme and onion and cook for 5 minutes.  Layer the potato, oil, Gruyère, mozzarella, salt and pepper in the frypan. If you don't have a frypan with a metal handle wrap it with foil before placing it into the oven. Bake for 45 minutes or until golden brown and cooked through.  Turn upside down to serve. Serve with a tossed salad.  Enjoy!