Bring a large pot of water to a boil. Cut a shallow 'X' cut into the bottom of each tomato and blanch in the boiling water for 30 seconds. Remove from the water with a slotted spoon and add to a bowl of ice cold water.
Remove the tomatoes from the water and remove the skins, they should come away very easily. Cut out the green stalk at the top of each tomato and roughly chop into quarters. Add the tomatoes to a food processor and blitz to a fine pulp. Pass the pulp through a sieve to remove the seeds and extra thick pulp. Set aside.
Bring another pot of salted water to a boil. Add 1 tbsp of olive oil to a large pan and add the garlic and oregano. Fry for a few seconds, don't let it brown and then add the tomato juice and a pinch of salt and pepper. Let it simmer for around 10 minutes until it has reduced almost by half and thickened slightly. Taste for seasoning.
Once the sauce is pretty much done, add the gnocchi to the boiling water, once they float on the surface of the water remove them with a slotted spoon and add them to the sauce. Toss to combine and serve in bowls with a grating of parmesan.