Pour 2000 ml water into a large pot, add 2 tsp salt and bring to a boil. While you wait, add 2 tbsp olive oil and 2 cloves garlic to a cold frying pan. Heat on low and fry until the garlic is lightly golden and fragrant. Remove the garlic pieces, they won't be used in this recipe but you can save them for another dish (great with salads, ramen etc)
Add the 50 g red onion and 1 anchovy fillet. Fry until the onion is slightly softened.
Once the onion is softened, add 200 g dry spaghetti to the pot of boiling salted water and cook until al dente (generally 1-2 minutes less than the packaging states).
Add 3 tbsp canned tomato and 3 tbsp white wine to the frying pan.
Mix well and then add 150 ml heavy cream. Gently heat it without boiling.
Once the cream is heated through and almost bubbling, reduce the heat and add ¼ tsp salt and 85 g sea urchins (uni) (optional: save 1 tsp of uni per serving for garnish). Break up the uni and mix it into the sauce.
Simmer the sauce on low until the pasta is ready. Add a small amount of pasta water to the sauce to make it glossy and stick better to the pasta.
Once the pasta is cooked, drain it and add it to the sauce. Turn off the heat and add 1 tsp butter.
Mix until the pasta is fully coated and the butter has melted into the sauce.
Place the pasta on serving plates and top with the reserved uni. Sprinkle with ground black pepper and fresh parsley, and enjoy!