In a large skillet, heat the oil at high heat.
Add the shrimp and season with salt and pepper. Sautee for 2 minutes, stirring to sear both sides of the shrimp. The shrimp will start turning pink and curl into a circle.
Add the sliced serrano peppers, followed by the tomatoes. Stir to combine and cook for 2 minutes more.
Turn the heat down to medium-low and add the orange juice and lime juice. Simmer for a couple more minutes to reduce down some of the juices.
Serve hot over the cooked grits and top with picked onions and a garnish of chopped cilantro.