Preheat the oven to 170ºC fan/190ºC conventional/gas mark 5.
Loosely line a large shallow oven tray with a large piece of Bacofoil Non-Stick Foil – remember to always place food on the dull side – and place the pieces of onion, pepper and courgette onto it. Drizzle with 1-2 tsp olive oil and gently toss together using clean hands. Roast in the oven for 20 minutes until the vegetables are just starting to turn brown round the edges.
Meanwhile make the dressing. Mix the passata, extra virgin olive oil and red wine vinegar in a small bowl. Chop the herbs, reserving a few whole mint leaves for garnish, and stir in to the dressing.
Remove the vegetables from the oven and add the cherry tomatoes and garlic. Season with a little pepper and carefully mix in. Scatter over the pine nuts.
Arrange the slices of halloumi over the top and return to the oven for a further 10 minutes. Alternatively place under the grill for a couple of minutes.
Drizzle with the dressing and scatter over the remaining mint leaves. Serve with some crusty bread.