Caramelised Onions

1. NB. For best time efficiency, caramelise the onions whilst the eggplant is in the oven (see below).
2. Heat a pan to a medium / high heat and add the olive oil.
3. Slice the onions and add them to the pan.
4. Sprinkle the 1/4 tsp salt over them and keep them moving for 10 to 15 minutes, until they are a deep brown.

Frittata

1. Preheat oven to 200C / 400F.
2. Line a baking tray with baking paper and arrange the eggplant cubes in a single layer. Bake these at 200c / 400F for 10 to 15 mins, whilst you caramelise the onions. If you want the eggplant a little more soft, bake them for 25 minutes, turning a couple of times to make sure they don't burn, since you're not using oil.
3. Whisk the eggs, milk, salt & black pepper.
4. Cut the feta into cubes and add to the eggs.
5. Once the onions are done, add them to the eggs. Use the warm pan on a low heat to slightly wilt the spinach. Add the spinach to the eggs.
6. Take the eggplant out of the oven and add to the eggs. Leave the oven on.
7. Line a baking pan with some baking parchment and pour the frittata mixture into it. I used a baking tin 14 inch (35cm) long, by 7.5 inch (19cm) wide and 1.5 inch (4cm) high.
8. Place the whole thing into the oven at 200C / 400F for 20 to 25 minutes.
9. Serve immediately, either on its own, with a little hot sauce, or with a green salad or a few boiled new potatoes.