In a pot over medium-high heat, add the sausage and cook until browned, about 5 minutes. Set aside. (If you use a vegetarian sausage substitute, add 2 tablespoons olive oil first)
Heat oil, and add the onion and celery. Cook until soft and beginning to brown, about 5-7 minutes.
Add garlic and cook for about 1 minute.
Add the orzo, spices, and tomato paste, and toast the orzo a bit, about 3 minutes.
Add back in the sausage, as well as the bouillon cube and the water.
Bring to a boil, then reduce heat to simmer. Cook until orzo is tender, about 15 more minutes.