Preheat your oven to 200°C (400°F, Gas Mark 6). Line a baking sheet with parchment paper.

Clean 400 grams of mixed mushrooms and cut them into uniform pieces. Toss them with 2 tablespoons of olive oil, a pinch of salt, and pepper. Spread them on the baking sheet.

Roast the mushrooms in the preheated oven for 20-25 minutes, or until they are golden and crispy on the edges.

While the mushrooms are roasting, prepare the sauce. In a small bowl, mix together 3 tablespoons of yogurt, 1 teaspoon of Dijon mustard, a squeeze of lime juice, and a tablespoon of finely chopped fresh herbs of your choice (e.g., parsley, cilantro). Season with salt and pepper to taste.

Warm 4 whole wheat pittas in the oven for the last 5 minutes of the mushroom roasting time.

To assemble, slice open the pittas and spread a generous layer of the sauce inside each. Add a layer of lettuce leaves and the roasted mushrooms.

Top with thinly sliced red onion and a squeeze of lime juice before serving.