Bake cod filets according to the directions on the box.
While the cod bakes heat a nonstick pan over medium heat. When the pan is hot, warm tortillas on both sides until soft but not brown. Remove from pan and set aside.
Add olive oil, salt, pepper, shallot, and garlic to the pan. Cook until soft, stirring constantly, about 1 minute.
Add tomato and lime juice to the pan. Bring to a boil and then reduce heat to low for 30 seconds.
Layer each tortilla with half a cod fillet, arugula, avocado, and sautéed vegetables. Serve.