Heat the oil in a large, deep saucepan over a medium-high heat and cook the veg mix, celery and garlic for 10 mins until the veg has softened and any excess water has evaporated. Mix in the onion granules, dried herbs, chopped tomatoes and stock. Bring to a simmer and cook for 20 mins until the liquid has reduced slightly. Season and add the lemon juice and parsley.

Meanwhile, for the croutons, heat the oil in a frying pan over a medium heat. Tip the sesame seeds onto a shallow dish and press the halloumi pieces in them to coat slightly. Fry, turning often until golden all over, about 5-7 mins. Divide the soup between bowls and garnish with the halloumi ‘croutons’ to serve.