Peel the potatoes and quarter or sixth lengthways, depending on their size. Halve these pieces crosswise and place in a high ovenproof pan with the well-seasoned vegetable stock. Stew for about 10 minutes until the broth is soaked up.
Add the vegetables cut into smaller pieces and the sliced onion and mix with a dash of olive oil. Briefly heat up the temperature, then switch back again. Cover the pan and gently fry the vegetables for another 5 minutes, until the pieces are cooked.
In the meantime, grate the parmesan and whisk the eggs with salt and pepper well. Add half of the cheese, pour over the vegetables and cover again.
Now heat the grill to 240 ° C. When the eggs are set, remove the lid, sprinkle with the rest of the parmesan and slide the pan under the heated grill for 5 - 7 minutes.
Serve with a green salad.
Note: Also suitable for cold meals, e.g., for the lunch box, a brunch buffet or a picnic