Pumpkin, ham and pesto lasagne

Ingredients

• about 800 gram pumpkin
• about 12 lasagne sheets
• 250 gram mascarpone
• 1 recipe for pesto or use about 6 tablespoons store-bought pesto
• large handful of peast
• 1 onion
• 2 garlic cloves
• pepper and salt to taste
• olive oil
• handful of pitted black olives
• 200 gram smoked raw ham slices (e.g. Serrano ham)
• handful grated cheese
• handful grated grana padano