In a large bowl, whisk the eggs and milk until smooth. Add the parsley, dill, and lemon zest.
Add the olive oil to an 8-inch pie dish. Add the vegetables, spinach, and smoked salmon to the oiled dish. Pour the egg mixture overtop, and sprinkle with feta cheese.
Bake for 16 to 18 minutes, or until the edges are browned and the eggs are set.