Heat your oven to 190ºC/Fan 170ºC/Gas 5. Fill the kettle and boil it. Trim the leek. Slice a cross in the top to open out the layers. Rinse it. Thinly slice it. Heat 1 tbsp oil in a deep frying pan or wok. Add the leek. Fry for 7–8 mins over a low heat till soft. Stir now and then. Take off the heat.
Tip the bulgar wheat into a pan. Pour in 250ml hot water from the kettle. Add a pinch of salt. Bring to the boil. Turn the heat right down. Cover and simmer for 8-10 mins. Drain. Grate or pare the zest from the lemon. Juice it.
Rinse the peppers and halve them lengthways. Scoop out any seeds and white bits. Place on a baking tray. Drizzle with olive oil. Bake for 5 mins, cut side up, to soften them a bit before filling.
Rinse the tomatoes. Finely dice them. Stir the tomatoes and a pinch of the dried oregano into the cooked leek. Stir in the bulgar wheat. Add the lemon zest. Season.
Pile the bulgar mixture into the pepper halves. Crumble half the pack of feta over the top. Drizzle with 1 tsp olive oil each. Bake for 10-15 mins or till the feta is golden.
While the peppers are in the oven, peel the beetroot. Dice it. Rinse the mint and pat dry. Finely slice the leaves. Halve and wash the cucumber. Scoop out the seeds using a teaspoon. Dice the cucumber.
Mix the beetroot, cucumber and olives together in a bowl. Squeeze a little lemon juice over the salad. Drizzle with 1 tbsp olive oil. Toss to mix. Serve with the stuffed peppers.