This tart is so "modest", unpretentious and tasty... You can use foie gras dough, either bought or made by yourself. Use the veggies you like or the ones you have in the fridge and want to get rid of so go for it.
What vegetables will I use today? Broccoli, carrot, celery, mushrooms, celery stalks, parsnips, zucchini, onions. You can also put cauliflower, bell peppers, spinach, green beans, peas, ... The quantities you adapt according to the dough you have and the number of portions you want to make.
Cut the vegetables into cubes and sauté them in the a little oil. You stop them while they're still al dente, don't soak them too hard as they'll also go in the oven and are better crispy, not mushy.
Add, grated cheese of your choice or what you have: grated telema, cheddar, more "stinky" cheese, grated mozzarella, any type of hard or aged cheese, I usually try to mix at least two types of cheese and not just put one kind.
Add beaten eggs (2-3) depending on the amount of vegetables you have and add them on top of the mixture.
Spread the dough in a tray. Put the vegetable mixture, cheese, eggs over the dough and put in the oven for 20-30'.