Preheat oven to 180c.

Grease a deep dish with 1 tbsp olive oil.

Mix the eggs together with salt and pepper.

Add the celeriac, onion and egg mixture into the dish, and mix to combine.

Use a fork or spoon to push down to get a tight mixture and flat top.

Drizzle 2 tbsp olive oil over the top of the celeriac mix.

Place in oven for about an hour, when the top should be brown and crispy, but not burning.