Bring Water to a boil in a large pot.

Add Salt to the boiling water.

Add 500 g Pasta and cook for 11 min, or according to package directions.

Dice the 2 Onions.

In a small pan, melt 20 g of butter over medium heat.

Add the diced onions and sweat until softened.

Add 2 cans of Tuna (drained) to the pan with the onions.

Pour in 500 ml Heavy Cream.

Season with Salt and Pepper to taste.

Add the juice from 1 lemon.

Stir well to combine and heat through gently.

Drain the cooked pasta, reserving a little pasta water if desired.

Add the drained pasta directly to the pan with the sauce.

Mix well to ensure the pasta is evenly coated with the tuna cream sauce. Serve immediately.