Preheat the oven to 350°F.
Grease or spray an 8-inch square baking dish with nonstick cooking spray; set aside.
Beat the eggs, milk, and seasoned salt together with a whisk in a large bowl.
Stir in the ham, cheese, and onion.
Pour the egg mixture into the prepared baking dish.
Bake for 40-45 minutes, or until the eggs are set and a knife inserted in the center comes out clean.
Cut into squares and garnish with fresh herbs, if desired.
