Heat a little olive oil in a pan and gently sauté the celery, onion, carrot, garlic, sweet potato, and red pepper for about 8 minutes, until softened.
Add the oregano, chilli and tomato purée. Stir for 1 minute.
Pour in the tinned tomatoes and then use the empty tin to add enough water to fully cover the vegetables.
Simmer for 20 minutes, then remove from the heat and stir in the fresh herbs.
Blend with a stick blender until smooth and thick.
Set aside half the sauce for another meal (it freezes well).
Bring a pan of salted water to the boil and cook the gnocchi according to packet instructions (usually 3 minutes, until they float).
Lift the gnocchi out with a slotted spoon directly into the pan of tomato sauce.
Reheat the gnocchi cooking water and blanch the edamame beans for 5 minutes.
Add the edamame to the gnocchi and sauce, stir well, and reheat gently if needed.
Serve immediately, with extra herbs on top if you like.