Slice each chicken breast, in half to create 4 flat chicken breasts (See top tip).
Take 3 bowls and place the flour, eggs and breadcrumbs into each bowl.
Gently heat the butter and oil in a shallow frying pan. When the butter has melted, dip a slice of chicken in the flour, then into the egg and then into the breadcrumbs (in that order), place in the pan and cook on each side for around 8 mins until golden and cooked through.
Repeat until all the chicken is cooked through. You may need to do this in 2 batches.
Slice and serve immediately with some salad, chips or pasta.