Fill a large pot with water and throw in a very generous pinch of salt.
Over high heat bring the water to the boil and then add in the Linguini.
Stir so that it does not stick and then while it cooks give it a stir every few minutes.
Cook according to the directions on the packet. If you put the pasta on and then cook the dish the pasta should be cooked just at the right time to drain and add to the sauce.
In a large fry pan heat the butter until melted and beginning to foam then add the onion and cook for several minutes until it becomes translucent and then add the garlic and cook for a further few minutes.
Remove the flowers from the zucchinis and reserve for garnish and roughly chop the zucchini and add it to the onion and garlic and cook until softened – about 5 minutes.
Add the cream and wine and bring to the boil then turn down and add the mustard and trout and stir through on a medium heat to warm the trout through.
Add the dill and season with salt and black pepper and stir.
Add the pasta into the pan with the tuna sauce and give it all a good toss to combine and tip into a large bowl which you can place in the middle of the table for people to serve themselves from.
Lastly scatter the torn zucchini flowers and the diced tomato over the top as a garnish.