Bring the brown rice and water to a boil in a saucepan over high heat. Reduce the heat to medium-low, cover, and simmer until the rice is tender and the liquid has been absorbed, 45 to 50 minutes.
Preheat oven to 350 degrees F (175 degrees C). Spray a baking sheet with cooking spray.
Place the red peppers on the prepared baking sheet, and bake until tender, about 15 minutes.
Heat the olive oil in a skillet over medium heat, and cook and stir the onion and garlic until the onion is translucent, about 5 minutes. Stir in the black-eyed peas and chard. Bring the mixture to a simmer, and cook until the chard is wilted, 5 to 8 minutes. Mix in the cooked brown rice, sprinkle with salt and pepper to taste, and lightly stuff the mixture into the red peppers. Serve hot.