Rinse beans. In a large saucepan combine beans and enough water to cover them. Bring to boiling; reduce heat. Simmer for 2 minutes. Remove from heat. Cover and let stand 1 hour. (Or, omit boiling and soak beans overnight.)
Drain and rinse the beans. In a 4- or 6-quart pressure cooker combine the beans, onion, red pepper, the 3/4 cup green pepper, garlic, jalapeno peppers, chili powder, cumin, salt, black pepper, and water.
Lock lid in place. Place pressure regulator on vent pipe (if you have a first-generation cooker). Over high heat, bring cooker up to pressure. Reduce heat just enough to maintain pressure and pressure regulator rocks gently; cook for 12 minutes.
Meanwhile in a medium mixing bowl stir together chopped tomatoes, 1/2 cup chopped green sweet pepper, avocado, green onions, lime juice, and cilantro.
Quick-release the pressure. Carefully remove lid. Serve with salsa and sour cream, if desired. Makes 4 main-dish servings (6-2/3 cups).
Prepare salsa; cover and chill up to 24 hours.