Melt butter in a large, heavy pot over medium heat. Add celery, carrots, and leek and cook until they just begin to soften, 4 to 6 minutes. Add water and crumble in bouillon cube. Stir in tomato paste, thyme, and garlic. Cover pot, reduce heat to low, and gently simmer for 10 minutes.
Stir salmon cubes into the pot and simmer for another 5 minutes. Add olives and parsley, mixing gently. Simmer for another 5 minutes.