Finely chop the onion, celery. Coarsely grate or spiralise the courgette. Mince the garlic and dice the Gorgonzola.
Cook the pasta according to the package instructions.
Meanwhile, heat the oil in a large saucepan, then gently sauté the shallot and celery over a medium heat. When the vegetables are soft and translucent, add the minced garlic and cook for another minute. Add the courgette and sauté for a couple of minutes until soft.
When the pasta is done, drain, reserving a cupful of the cooking water.
Combine a couple of Tbsps of the cooking water with the cheese, stirring it to melt.
Add the parsley or basil to the courgette, then pour over the cheese sauce. Simmer for a minute, add the lemon juice and taste. Season with salt and pepper to your liking.
Add the pasta to the cheese & courgette sauce. Keep simmering, while tossing to coat the pasta completely. Add more reserved cooking water if the sauce seems too thick.
Serve warm with ground pepper or chilli flakes scattered on top.