1. Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius).
2. Place eggs in a mixing bowl and beat with a fork. Add flour and milk and beat with a fork until all the ingredients are combined.
3. Add mayonnaise and mix until combined. Add your chosen fillings, and pour into the pie shell.
4. Bake for 40–45 minutes, or until top is just browning and center is firm to the touch.