Potato and Roasted Capsicum Frittata with Truffle

Peel the potatoes and chop them into small cubes. Place in a saucepan, cover with water, and add the vinegar. Bring to a boil and simmer until the potatoes are just tender but not falling apart. Drain and allow to air dry.

Heat oil in an ovenproof frying pan over medium heat. Add the potato and cook, tossing occasionally, until the potato is browned all over. While the potato is cooking, dry the capsicum on paper towels and cut it into strips. 

Make the egg mixture by breaking the eggs into a bowl and whisking. Add the mustard, whisking well after each addition to incorporate it thoroughly. Add the sour cream and whisk again. Add the grated cheese and stir until well combined.

Once the potato is browned all over, add the capsicum and cook, stirring to distribute the ingredients evenly. Pour the egg mixture over the top of the potatoes and capsicum. Tilt the pan to cover evenly. Cook on medium heat, using a spatula to neaten the edges and gently lift them from the sides of the pan. Once the base is browned (lift an edge to check), place the pan under a hot grill. Cook until fluffed and well browned.

Remove from the grill and allow to sit for a minute. Work the sides of the frittata with a spatula to lift it from the pan. Place a chopping board or plate over the top and flip the pan, allowing the frittata to fall onto the board, displaying the cooked potato. 

Cut into wedges to serve.