Soak peas, if required, after washing and picking them over. In a large saucepan, place peas, onion, pepper, and bay leaf. Add 6 cups water and bring to a boil over high heat, then turn heat down to simmer. Cook, uncovered, until peas are tender but still firm, about 30 minutes. Add the salt and cook 2 more minutes. Drain peas; discard liquid. Place peas in a bowl. In another bowl, whisk the lemon juice, olive oil, garlic, and oregano together. Pour over the peas and toss gently to coat evenly. Season with additional pepper to taste; add more salt, if needed, and lemon zest. Serve at room temperature or chill, covered, until 20 minutes before serving. Leftovers are delicious in pita bread. Serves 8-12.