Heat two tbsp of oil in a large non-sticking pan, and cook the salmon fillet for 1 minute per side (the center must be almost raw). Season with salt and set apart.
Add 2 more tbsp of oil to the pan, sauté the leek for 3 to 4 minutes until soft, and cooked through. Season with salt. Shred the salmon and add to the pan.
In the meantime, cook the Tortelloni according to package instructions and drain, reserving a ladleful of the pasta cooking water. Add the pasta to the pan and stir gently, adding some of the pasta water if you need to loosen the sauce.
Divide among 2 plates, drizzle with little oil, sprinkle with pink peppercorns and serve.