Mix all of the ingredients, except the milk, together in a small bowl. Use milk to thin the sauce to a drizzling consistency, adding a little at a time and stirring in. Set aside.
Spiced Tomato Sauce
Heat a large frying over medium-high heat. Heat a glug of olive oil, then add the pepper, onion and cloves. Fry until the veggies begin to soften. Add the tomato paste, garlic, cumin, coriander, paprika, nutmeg and chillies and fry for 2 minutes until fragrant. Add the tomatoes, water, sugar and bring to a boil. Reduce heat and simmer for 10 minutes.
Season the hake fillets with salt and pepper, then place into the tomato sauce. Cover with a lid and cook for 8 minutes.
Portion the cooked couscous onto serving plates. Add a hake fillet with spoonful’s of spiced tomato sauce to each. Drizzle with tahini sauce and garnish with chopped mint and a sprinkling of pine nuts.