Heat oven to 375°F Mix eggs and cheeses in a large bowl until well blended. Stir in the broccoli, mushrooms, tomatoes, and onions.
Unroll the crescent dough and separate into 16 triangles. Arrange on cookie sheet, covered in parchment paper, in an 11" circle with short sides of triangle overlapping in center and points of triangles toward outside.
Spoon cheese mixture onto dough near center of circle. Bring outside points of triangles up over filling, then tuck under dough in center of ring to cover the filling.
Bake 35 - 40 min, or until crust is golden brown and filling is heated through.