Heat the vegetable oil in a saucepan over medium-high heat. Add the onion and garlic to the pan and cook until the onion is translucent. Season the mixture with salt, and pepper, to taste. Add the rice, stirring to coat the grains in the oil. Pour in the water, and stir to separate the rice. Bring the ingredients to a boil, and at this point, reduce the heat to a simmer, and place a lid over the pot. Cook the rice until tender, about 15 minutes.
Add the black eyed peas to the pot 5 minutes before the end of the cooking process.
Transfer the finished dish to a bowl, let it cool slightly, and garnish with the mint.