INGREDIENTS
2 tbsp
butter
1
medium-large yellow onion, thinly sliced
1 tsp
fresh thyme leaves
1 tsp
sugar
1/4 tsp
salt
Freshly ground black pepper,
2 tbsp
white wine (optional)
1/2 cup
ricotta cheese
1
egg yolk
1
sheet frozen puff pastry, thawed (or 1 half batch
homemade puff pastry
)
1/4 cup
shredded Parmesan cheese
Minced fresh parsley, for garnish