Set the water for the pasta. While the water cooks, prepare the rest.
Drain the tuna. Set aside.
Chop the capers and the anchovies very finely. Place them in a bowl and pour in the heavy cream, add the eggs, salt, pepper, oregano. Whisk well.
Grate the Parmesan and add it to the bowl. Stir again. Set aside.
Once the pasta water is cooking, add salt generously. Cook the spaghetti according to the packet’s instructions. Drain. Return the pasta to the empty pot.
Flake the drained fish on top.
Turn on the hob again on low heat. Pour the egg mixture on top and stir very quickly to combine everything for 30 – 40 seconds, until the sauce is creamy and the pasta is coated with it. Do it very shortly and on low heat or the eggs might scramble.
Sprinkle with chopped fresh herbs and serve immediately with more grated Parmesan if desired.