In a medium saucepan heat up 2 tablespoons of oil, add the bay leaf, garlic and onion and saute on a low heat for 3-4 minutes, stirring occasionally. Add the tomatoes, tomato paste, brine from 1 tuna tin, season, cover and simmer for 7 minutes.
In the meantime in a large pan heat up 2 tablespoons of oil and fry the squash cubes on a high heat for about 7-8 minutes stirring often until softened and lightly browned. Remove from the heat and place in your oven dish.
In the same frying pan heat up the spinach and cook over a fairly high heat until reduced in size, for about 1 minute, stirring all the time. Stir the spinach mixture into the tomato sauce. Adjust the seasoning if necessary.
Spread the tuna over the squash, pour the sauce over the whole thing, top with feta, drizzle with a little oil, sprinkle some paprika and bake for 30 minutes. If the feta starts to brown too much cover loosely after 20 minutes.
To serve garnish with parsley and enjoy with pasta, quinoa, potatoes, couscous, crusty bread or simply on its own.
You will need to use tuna in water rather than oil (you will use some of the water in the recipe).
The spinach will need only about a minute of frying. Once it wilts down it is ready to combine with the sauce.
Serving: Serve with pasta, potatoes, rice, quinoa, couscous or slice of crusty bread (there'll be lots of sauce to soak up!). Sprinkle over fresh herbs, such as chives or parsley.
Refrigerate leftover tuna bake in an airtight container for up to 3 days.
Freezing: Once cooled transfer into an airtight container and freeze for up to 3 months. To defrost place in the fridge overnight and reheat in the microwave.