Slice and deseed the tomato and sprinkle with salt and sit for 30 minutes on absorbant paper
Remove lots of moisture before frying in a non stick frypan till charred. (5 mins) Set aside and keep warm.
Boil the pasta for 1 minute less than the suggested time. I like thick hollow pasta in this dish. So 12 mins
Cook the button mushrooms in 2 Tbs of the margarine till softened (6 mins) and set aside with the tomato.
Melt 1 Tbs of the margarine in the frypan and remove from the heat. Tilt the pan to form a pool
Add the minced garlic to the melted margarine and let infuse off the heat. 
When the spaghetti is just al dente lift with tongs and add to the frypan and toss through the garlic butter
Add 2 Tbs of Greek yogurt and the anchovies to the frypan and toss through 30 seconds over the heat. 
Then add the mushrooms, tomatoes, salt and pepper. Toss through and plate

In the same frypan over medium heat cook the Tuna for 40 seconds a side and then roll the edges to brown.
Slice to 4mm thick and sprinkle with lemon juice and season. Place over the pasta. 
Add seasoned avocado slices between the tuna slices.
Add dobs of the remaining Greek yogurt.

Top with some shredded cheddar and parmesan cheese.

Optionally, you can stick the plate under the grill for 30 seconds to brown off the tuna and melt the cheese a bit. Some people don't like seeing the rather raw protein that I like. As pictured. Both ways are good.

Serves 2 large or 4 small portions at about 700 or 350 calories a serve.

240g Tuna Steaks
150g Thick Spaghetti
3 cloves minced Garlic
Salt Pepper
3 Tbs Greek yougurt (sour cream)
3 Tbs Omega 3 Margarine (butter)
100g Button mushrooms sliced
2 Tomatoes deseeded and salted
4 Anchovies chopped roughly
1 small Avocado cut into slices
Lemon juice
Parmesan Cheese
Cheddar Cheese

Fresh wild caught Tuna is something else but where do you get it and how much do you have to pay.

I usually buy Yellow Fin frozen tuna steaks from the supermarket. Good product. The trick is to remove it from the freezer just 90 minutes or so before cooking otherwise the texture will become a little mushy with the loss of too much moisture. Pat dry before cooking so it fries rather than stews. 

For all of us it has become necessary to start tempering what we eat. This is a combination of many healthy ingredients and superfoods put together in a very palatable way. In fact this is so tasty you don't need to eat it just because its healthy. A true modern classic recipe. There is debate about the benefits of omega 3 margarines and vegetables oils. From the cholesterol lowering standpoint its a winner. However you can substitute butter for margarine, sour cream for greek yogurt and its great. Once the pasta goes in the boiling water this is a very quick dish to cook. Think about the timing of each element around the pasta cook time.

The basic idea of most restaurant chefs compared to home cooks is add lots more salt, fat and msg. Even when reading a list of ingredients that make you feel like you are eating healthy, it may be overwhelmed with calories and unwanted salt. Take some salad ingredients and make it palatable with a creamy salad dressing and its not hard to add 500 calories with just 2 heaped spoonfuls of dressing. 1 level tablespoon of oil or mayo is 150 calories. Watch a celebrity chef cook. A handful of salt and load it up with Olive oil. Frightening.