This is really simple, but incredibly delicious, and great to share!
Fantastic as part of a mezze to share with friends, served straight out of the oven when the feta is soft and spreadable and mingling with the chunky tomato sauce, with crusty warm bread to scoop it up - I can guarantee it will all disappear in minutes if not seconds!
Easy to make, and hard to go wrong - you can even prepare it the day before and just pop it in the oven when you're ready to go.
Serves four as an appetiser / snack with a 200g baton of crusty bread, or six with a couple of other dips and some crudites (vegetable batons, e.g. carrot, cucumber, peppers etc.). Easily doubled. From 145 calories for the baked feta in tomato sauce alone, or 279 calories per portion including bread (see below).
Calories, if you're counting - 895 for the whole baked feta in tomato sauce (including 1 tbsp oil drizzled over), or 580 using lighter cheese and no drizzle of oil. 536 calories for a 200g small white baton of crusty bread. So, between four people; 279 calories each for the lighter option (including bread, 145 without), or 358 calories per person for full fat feta and a drizzle of extra virgin olive oil (224 excluding bread). [Calories in square brackets]
200g good feta cheese (you could use lighter Greek salad cheese if you're trying to cut calories, vegetarian feta available) [560 / 380 lighter]
Extra virgin olive oil, to drizzle (optional, 1 tbsp) 
A few fresh oregano leaves (or you could use little Greek basil leaves, optional) 
For the sauce
1/2 an onion (50g) 
Olive oil (1 tsp) 
2 small garlic cloves 
400g (tin) chopped plum tomatoes 
1 tsp red wine vinegar (or balsamic) 
1 tsp dried oregano 
A pinch or two of dried chilli flakes/crushed chillies, to taste (optional) 
1 tsp sugar 
Salt and freshly ground pepper to taste 
A small handful of olives, roughly chopped or a few sun-dried tomatoes, roughly chopped, stirred into the sauce before baking; a scattering of pine nuts sprinkled over the top before baking.
Traditional Greek bread, if you can get it (e.g. a crusty daktyla country loaf, topped with sesame seeds), or a small crusty white baton (200g - 536 calories in total, if you're counting) or gluten-free bread (DS brown seeded ciabatta rolls are good warmed up).
Firstly, make the tomato sauce. Finely chop the onion and slice the garlic cloves (Thermomix, drop onto running blades, speed 4). Fry the onion over a low heat in the olive oil until softened then add the garlic and continue to cook for another minute or two until fragrant (make sure it doesn't catch or burn or it will taste bitter) (TM add the tsp oil and cook 5 minutes / 100C / Speed 2 / Reverse Blade Direction). Add all of the other sauce ingredients, turn the heat up, and bring to a gentle simmer and turn the heat down again. Simmer for 25-30 minutes over a low heat until reduced to a pulpy texture (TM add the other ingredients, mix 2 seconds / Speed 4, and then cook 20 minutes / 100C / Speed 2 / Reverse Blade Direction with the MC at an angle to reduce spitting, or until the sauce is pulpy). Stir in any optional extras if using and set aside to cool (if you're preparing it for later, or the next day, then you need to cool it right down).
Break the feta into larg-ish chunks (the size of cherry tomatoes) into an oven-proof dish that will fit them reasonably snugly (but not jam-packed) and pour over the tomato sauce, leaving some feta chunks showing, peeking out of the sauce. Either refrigerate if you want to cook and serve it later, or pop into a pre-heated oven gas mark 6 / 200C (180C fan) / 400F for 20 to 30 minutes until bubbling. If you're serving with crusty bread, you could pop it into the oven for the last few minutes to warm it through.
Cut the bread into small chunks or slices, and drizzle the baked feta with extra virgin olive oil (if using) and scatter with fresh oregano or Greek basil leaves and serve immediately.
If you're having a bit of a Greek mezze, why not try my Greek spinach and feta filo pie on the side (302 calories for a main portion), along with my Greek salad (79 calories for a side portion), and make a meal of it?
And if you're really going for it, you could whizz up this easy Orange, Pistachio and Cardamon Greek-inspired cake and serve with Greek yoghurt, to finish off... (this slice is about 175 calories a 'normal' sized slice would be 353 calories the cake serves 12-16). Eviva!