Preheat broiler, grill or grill pan.
Toss the fish into a large bowl with the juice from 2 1/2 lemons, hot sauce, 1 tablespoon EVOO, salt and freshly ground black pepper. Skewer 2 pieces of fish onto a metal skewer followed by a bay leaf. Repeat this process until the skewer is full, then repeat until all the fish is used up. You should have about 3 skewers of fish.
Thread the red and yellow pepper chunks and onion wedges, repeating every other until the two skewers are full. Onto the remaining 2 skewers, thread the cherry tomatoes until they are used up.
Place the pepper-onion skewers on the grill. After 2 minutes, rotate them and place the fish skewers on. After 2 more minutes, rotate the pepper-onion and the fish skewers and place the tomatoes skewers on the grill. In another couple minutes or so, check all of the skewers; they should be golden brown, tender. Remove them from the grill and reserve.
While the skewers are cooking, bring the chicken stock up to a boil. Add in the lemon slices, chopped green olives, salt and freshly ground black pepper, then whisk in the couscous. Turn off the heat, cover, and let sit about 5 minutes.
In a food processor, add the toasted pine nuts, parsley, mint, garlic and Parmigiano, and pulse until finely chopped. Stream in olive oil, pulse until combined and reserve.
In a medium-size mixing bowl, mix together the yogurt, cucumber, onion, lemon juice and zest, cumin, salt and freshly ground black pepper.
When the couscous is ready, fluff it with a fork then stir in the pesto. Serve the skewers over the couscous with the yogurt dipping sauce and grilled or toasted flatbread alongside.