In a large saucepan set over medium heat, add oil. Cook andouille sausage for 3 to 5 mins or until starting to brown; set aside.
Stir in onion, celery, thyme and garlic. Cook for 3 to 5 mins or until fragrant and softened.
Stir in rice. Cook for 2 to 3 mins or until well coated. Stir in broth, tomatoes, Cajun seasoning, cumin and salt. Bring to a boil. Reduce heat to low. Cover and cook for 20 to 25 mins. Remove thyme sprigs.
Stir in reserved sausage, 2 sliced green onions, lemon juice, red and green bell peppers. Cook for 5 to 8 mins more or until bell peppers are tender crisp. Stir in crab.
Transfer to serving bowl or serving plate. Garnish with remaining green onion.
Tie thyme sprigs with twine for easy removal.
Substitute andouille with cured chorizo for variation.
Substitute fresh crab meat with canned crab meat if desired.
Steam crab for 10 to 20 minutes to prepare.