Preheat the oven to 425 F, and line a baking sheet with parchment paper.
Rub 1 tablespoon of olive oil over the fillets and sprinkle them with ¼ teaspoon of salt and ¼ teaspoon of pepper. Top each of the fillets with a thinly cut lemon slice, reserving the remaining lemon.
Bake the mahi mahi for 10 minutes and remove from the oven. Allow the mahi mahi fillets to sit for 2 minutes.
Meanwhile, toss the cooked rice with the juice from the remaining lemon, the remaining 2 tablespoons of olive oil, ¼ teaspoon of salt, ¼ teaspoon of pepper, dill, and parsley.
Divide the rice onto 4 plates and finish each plate with a piece of fish and a sprinkle of herbs.