Remove the stamen at the base of the blossoms. Gently rinse to remove any traces of dirt or insects. Pat dry.
Prepare the ricotta filling
Preheat oven to 350F.
Sauté the diced onion in olive oil until golden. Transfer to a bowl and let cool a few minutes.
In a medium sized bowl combine the onion, ricotta, eggs, milk, parmesan cheese, basil and salt and pepper, to taste. Set aside while you prepare the filo tart base.
Assemble the tart
Unroll the sheets of defrosted filo dough on a flat surface and cover with a damp cloth to prevent them from drying out.
Layer a sheet of filo on a 9- inch pie plate and brush the bottom and sides with the melted butter. The edges of the dough will hang over the sides of the pie plate.
Rotate the pie plate 45 degrees and place another sheet of filo dough over the first sheet. Brush with melted butter.
Continue rotating the pie plate and adding the remaining sheets of filo, brushing each with the melted butter.
Pour the ricotta mixture into the pie plate.
Arrange the zucchini blossoms over the ricotta mixture in a circular fashion.
Fold the edges of the filo dough over the filling and brush with the remaining melted butter.
Bake for 30 minutes until the center has set and the filo is golden brown. Let sit for 10 minutes before slicing.
Notes
Be sure to keep filo dough covered with a damp cloth to prevent the sheets from drying and tearing.
Unused filo dough may be refrozen.
When you remove the tart from the oven the center may be slightly jiggly but will set as the tart cools.
Keep leftovers refrigerated for up to 3 days.
Please note that the nutritional information is approximate and may vary according to exact ingredients used as well as portion size.