Drain and slice the pimientos.
Halve the green pepper and discard the core and seeds.
Cut the flesh into cubes.
Cut the sausage into 1/2-inch cubes and sprinkle with the pepper and mustard.
Cut the cheese into cubes the same size as the sausage.
On each piece of sausage place a cube of cheese, then a slice of pimiento and a slice of green pepper.
Spear with a toothpick.
Heat the oil and butter in a frying pan and fry the kebabs until lightly browned on all sides.
Drain on paper towels and serve hot.