Thaw frozen Birds Eye Vegetables in fridge overnight. Before use, drain any excess liquid.
Heat oil in a tagine or Dutch oven over medium heat. Add garlic, cinnamon, ginger, spices and harissa paste, cook for 2-3 minutes.
Add tomatoes, chickpeas and preserved lemon and cook for a further 2-3 minutes. Add thawed roast vegetables and fill tagine halfway with vegetable stock. Bring to simmer, stirring occasionally, checking to see if there is sufficient liquid. Scatter over raisins. Cover and simmer on low for 20-25 minutes.
Meanwhile place couscous in a bowl and pour over boiling stock. Stir and cover for 5 minutes. Use a fork to separate the grains then add butter, currants and pistachios. Mix through chopped parsley and dill.
Place couscous in serving bowls and top with tagine and garnish with fresh herbs.
Once vegetables are thawed, use within 24 hours.