For the salad, melt the butter and olive oil in a frying pan over a medium heat, add the butternut squash and fry for 6-8 minutes, or until softened and golden-brown.
Place the herbs into a large bowl, add the squash and olive oil and stir well.
Return the frying pan to the heat, add the serrano ham and fry for 3-4 minutes, until golden-brown and crisp.
For the dressing, place the broad beans, balsamic vinegar, olive oil and mint into a small saucepan, season with salt and freshly ground black pepper and warm gently over a low heat for 2-3 minutes.
To serve, place the salad onto a plate, top with the crisp serrano ham and pour over the warm dressing.