Method:
Carefully pick through peas to remove any debris or small stones and rinse well. Transfer to a large bowl, cover by 3 inches with water, cover and set aside at room temperature for 8 hours or overnight; drain and rinse well.
Transfer peas to a medium pot. Add 3 cups water and bring to a boil. Reduce heat, cover and simmer until peas are tender but still whole, about 45 minutes. Drain well.
Heat 1/2 cup broth to a simmer in a large skillet over medium-high heat. Add onion, garlic and chard stems and cook, stirring occasionally, until vegetables begin to soften, about 5 minutes. Reduce heat to medium-low, cover and cook 5 minutes more. Add chard leaves, cooked peas, pepper, and remaining 1/4 cup broth and cook over medium heat, covered, 3 minutes. Uncover and cook 1 to 2 minutes more or until chard is wilted and peas are heated through.