Preheat oven to 210C/190C fan forced. Line 2 baking trays with baking paper. Place the carrot, capsicum and onion on prepared trays. Drizzle with 2 tbs of the oil. Season. Toss to combine. Roast, stirring halfway, for 35 minutes or until golden and tender.
Meanwhile, place the red quinoa and water in a small saucepan over medium heat. Bring to the boil. Reduce the heat to low and cook, covered, stirring occasionally, for 14-15 minutes or until tender. Rinse under cold running water. Drain well.
Combine the lemon juice, harissa, honey and 25ml of the remaining oil in a bowl. Season.
Place the roast vegies, quinoa, herbs and half of the dressing in a large bowl. Gently toss to combine.
Heat a non-stick frying pan over medium-high heat. Spray with olive oil. Cook the haloumi, turning, for 3-4 minutes or until golden. Transfer to a plate. Add the remaining oil. Add the seed mix. Cook, stirring, for 1 minute or until toasted. Top salad with haloumi, drizzle with remaining dressing and sprinkle with seed mix.