Heat oil in a 8 to 10 quart heavy bottomed pot. Add onion, garlic and sweet peppers; cook until peppers are tender, 8 minutes. Add salt, black pepper, thyme, pepper flakes and turmeric; cook 1 minute. Add broth, water, peas and shrimp. Simmer, covered, 2 minutes.
Remove from heat. Stir in couscous; cover; let stand 5 minutes. Serve, garnished with olives.