Tantalizing White Onion & Tuna Tart

20
May

Ingredients:

2 sheets of ready-made frozen puff pastry, thawed according to instructions
2 generous tbsp butter
3 large white onions, peeled, halved, and sliced thinly
3 large eggs
1 cup cream
salt and freshly ground black pepper to taste
pinch of freshly ground nutmeg
1/2 cup fresh ground mild flavored cheese, such as gruyere, asiago, or mild cheddar
1 lbs of mildly flavored fish fillets, I used wild tuna, cut into 1/2″ thick chunks