1.
Preheat the oven to 160°C.
2.
Place butter, garlic, parsley and chives in a bowl, season with sea salt and pepper, and beat until combined. Make a little hollow in the centre of the bottom half of the baguette and spread thickly with the garlic butter - you won't use all the butter, so reserve the remaining for the frittata.
3.
Press the halves back together and wrap the baguette loosely in foil, leaving the top crust uncovered, and set aside.
4.
To make the frittata, break the eggs into a bowl, add parsley, chives, cheese, a little salt and the reserved garlic butter and stir to combine.
5.
Melt the extra plain butter in a non-stick frypan over very low heat. Pour in the egg mixture and use a wooden spoon to pull back from the edges of the pan (allowing uncooked egg into the gaps), and cook for about 5 minutes.
6.
Cover with a lid or baking tray and allow the omelette to continue cooking for 2-3 minutes or until set. (Alternatively, place under a grill at medium heat to finish cooking.)
7.
Meanwhile, place the baguette in the oven for about 2 minutes to warm through. Slice the frittata into wedges. Remove the top half of the baguette and place the slices of ham and wedges of frittata all along the baguette. Replace the top and cut into 6 sandwiches. Serve warm.