(Vegetarian) Mediterranean Haloumi, Pesto & Onion Jam Burger

While the potatoes are roasting, thinly slice the brown onion. Heat a drizzle of olive oil in a medium frying pan over a medium-high heat. Add the brown onion and cook, stirring, for 5-6 minutes, or until soft. Add the warm water (see ingredients list), brown sugar and 1/2 of the balsamic vinegar, and simmer until the liquid is nearly evaporated and the mixture is slightly sticky. Season with a pinch of salt and pepper.

While the onion is cooking , cut the haloumi (see ingredients list) lengthways into 1 cm slices (you should get 2 pieces per person). Heat a small drizzle of olive oil in a second medium frying pan over a medium-high heat. TIP: Haloumi releases liquid as it cooks so you don't need much olive oil! Add the haloumi and cook for 2 minutes on each side, or until golden. Transfer to a plate and set aside.

Return the pan to a medium heat. Slice the hamburger buns in half and place, cut-side down, in the pan and toast for *2-3 minutes**, or until golden.

Thinly slice the roma tomato.

In a medium bowl, combine the mixed salad leaves (keep some plain for the burgers) with the remaining balsamic vinegar and olive oil (1 tbs for 2 people / 2 tbs for 4 people). Season to taste with a pinch of salt and pepper. TIP: Toss the salad just before serving to prevent soggy leaves.