Place Tilapia Fillet (2) on a plate and squeeze the juice from half of the lime over it. Season with the Ground Cumin (1 teaspoon), Chili Powder (1 teaspoon), Salt (to taste) and Ground Black Pepper (to taste). Turn the filets over and repeat on the other side.
Refrigerate fish and let marinate while you make the corn ceviche and rice.
Chop and remove the seeds from the Jalapeño Pepper (1). Chop the Scallion (1) and Fresh Cilantro (1 bunch). Shuck the Corn (2 ear) and use a sharp knife to cut off the corn kernels from all sides. Put corn in a mixing bowl.
Add the zest and juice of half the Lime (1), olive oil (1), green onion, and jalapeno to the corn and stir to coat. Add half the cilantro and salt and give it another stir. Allow flavors to blend for 10 minutes. Taste for salt.
Bring 2 cups water to a boil, then stir in the Butter (1 tablespoon) and Long Grain White Rice (1 cup). Cover and reduce heat to low. Simmer until rice is tender, about 15 minutes.
Stir in remaining lime zest, juice, and cilantro into the cooked rice before serving. Add salt and pepper to taste if desired.
In a large skillet, heat olive oil (1 Tbsp) over medium heat. Add fish and cook until outer edges are golden and fish flakes easily, about 5-6 minutes on each side.
To assemble tacos, place a few pieces of the flaked fish into a warmed Tortilla (4), top with spoon full corn ceviche and extra cilantro if desired.
Serve warm with the cilantro lime rice.