Heat one tablespoon of olive oil in a frying pan. Season the mutton fillet with salt and freshly ground black pepper and fry for 5-6 minutes, turning frequently, until cooked through. Remove from the pan and set aside.
Heat the remaining tablespoon of oil in the pan and gently fry the pear slices until they start to caramelise.
For the dressing, whisk all the dressing ingredients together in a bowl. Pour over the lamb's lettuce in a bowl and stir well to dress all the leaves.
To serve, place the dressed leaves onto a serving plate and arrange the pear slices on top. Slice the mutton fillet and arrange on top. Scatter over the cheese.