For the pesto roast the cashew nuts in a small pan without fat, until they are golden brown. Combine the basil, cashews, garlic and parmesan and blend everything together with a stick blender. Add olive oil until you have a smooth paste. Add salt and pepper to taste. (Alternatively you can use a small food processor for making the pesto or what I like to use sometimes: pestle and mortar. You definitely need less oil for the pesto of you use this method.)
Heat a splash of olive oil in a large pan.
Cook the ravioli according to package and save ½ cup of the cooking water.
Wash and dry the asparagus. Cut them up into 2 inch pieces, separating the heads from the stalks. We don't want to overcook the delicate heads.
Add the asparagus stalks to the heated pan and fry for 3-4 minutes.
Add the pancetta and dried tomatoes and cook for another 3-4 minutes.
Add the asparagus heads and cook for another 3-4 minutes, stirring occasionally.
Spoon in the pesto and stirr carefully until everything is coated. Season with salt and pepper to taste.
Add the drained ravioli together with the cooking water and toss until everything is coated.
Serve with some freshly grated parmesan cheese.