Preheat oven to 250°F.
Season the fish on both sides with salt and pepper. Mix flour with cumin, coriander, chili powder and sesame seeds, and coat fish on both sides.
In a large, nonstick skillet over medium-high heat, heat olive oil, 3 turns of the pan. When oil smokes, add fish and brown 3 minutes on each side, pressing on filets to keep them from curling. Transfer to baking sheet and keep warm in oven.
Add a little more oil to pan, a turn of the pan, then add onions, garlic, salt, pepper, thyme and oregano, and stir a minute or two. Add tomatoes and cover pan until tomatoes burst (if using fresh) or partially cover to simmer canned tomatoes with onions. Stir olives into sauce along with lime juice, cilantro and parsley; adjust seasoning, add fish to sauce then transfer to plates and serve with soft tortillas for wrapping.