Recipe for 4 portions
1. Cook the couscous
Bring 800ml lightly salted water to a boil in a medium pot. Add the pearl couscous to the boiling water and stir. Reduce the heat to low and let simmer covered for 8–10min. until all the water is absorbed and pearl couscous cooked through.
2. Marinate the tuna steaks
Meanwhile, in a bowl big enough to hold the fish, mix the cumin-coriander spice mix with 3Tbsp olive oil and ½tsp of salt. Wash and pat the tuna steaks dry, then coat them in the marinade. Set aside to marinate until ready to grill.
3. Marinate the onions
Peel and halve the onions, then cut 3 onion halves into fine strips. Use the rest of the onion in another recipe. Zest, then halve and juice the limes. In a large bowl, mix 2Tbsp olive oil and 1Tbsp vinegar with the zest, ½ of the lime juice and ½tsp of salt and pepper. Add the sliced onion and set aside to marinate.
4. Make the salad
Slice the coriander coarsely including the stalks. Halve the avocados, remove the pit and score the flesh crosswise. Use a spoon to scoop the avocado cubes out of the skin. Reserve a few onion slices from the bowl as a topping for later, then add the coriander and avocado to the bowl. Add the cooked pearl couscous and mix to combine into a salad.
5. Grill the corn
Drain the corn kernels in a sieve. Heat up a grill pan or large normal pan on medium-high heat. Add 1Tbsp vegetable oil and fry the corn kernels for 6–9min. until they are nicely charred. Season with a ½tsp of salt and then add the corn kernels to the pearl couscous salad. Wipe out the pan.
6. Grill the tuna steaks
Wipe out the pan and set it back on a medium to high heat. When hot, add 1Tbsp vegetable oil and grill the tuna steaks on each side for 2–3min. to the desired doneness. Season the pearl couscous salad with the rest of the lime juice and salt and pepper to taste. Serve the grilled tuna steaks on top of the pearl couscous salad, garnished with the reserved marinated onions.