I think you're right- fritatta.
Potato and Onion Fritatta
8-10 eggs, beaten
1/2 cup milk or butter milk
3 large potatoes, cleaned and slice
2 large onions, chopped
Rosemary, salt and pepper to taste
1/2 cup or more shredded Parmesan or Romano cheese
Olive oil and/or butter
The basic approach: saute the onions and potatoes until they have some brown on them. (If you are making this in huge amounts, you can steam the potatoes instead.) Season with some rosemary, preferably fresh, but dried will do, and some salt and pepper.
*This can be done the night before.*
In a large, preferably cast iron, pan, heat olive oil and/or butter. Don't skimp. No one will confuse this for a low fat dish anyway. Then add beaten egg/milk mixture. (I find that the buttermilk gives a particularly good texture, but any sort of milk is not at all traditional in this dish.) When it begins to set, add the potato and onion mixture and cook on the top of the stove until fully set. Then top with cheese and brown under the broiler for 30-90 second. (Alternatively: make the dish in shallow ceramic
bakers. Heat oil/butter, add egg and let it set briefly. Then
add the other mixture and bake -- perhaps 15 minutes, but keep an eye on it -- at 350 degrees F. Top with cheese and broil as above.) I think the dish is even better when made on the stove, but I often use the oven approach if I'm making several and don't have time to attend to them.