In a 6-quart heavy pot with lid, heat oil over medium heat and add the pinch of crushed red pepper, cooking for 30 seconds. Tip in fresh vegetables: onion, leeks, celery, fennel, garlic, green pepper. Season with salt and pepper, chili powder, coriander, cumin, parsley and bay leaf. Cook, stirring, 6 or 7 minutes without browning.
Pour in liquids --clam juice, broth, water--along with the beans and drained tomatoes. Cover and bring to a boil. Taste and adjust seasonings. Cook 20 minutes partly covered or until vegetables are all quite tender.
Stir in the crab. Heat through and simmer a few minutes. Toss together the green onion, green pepper, and cilantro for a fresh salsa garnish and set aside briefly. Taste and adjust seasonings. Serve hot garnished with the fresh green onion salsa and grated cheese.
Whoever gets the bay leaf does the dishes. (Store leftovers tightly covered for no more than 48 hours.)