Heat a medium-large dutch oven or pot over medium heat. Add oil, onion, celery, and carrots. Sauté for 2-3 minutes.
Add in potatoes and garlic stirring constantly until garlic is fragrant, careful not to burn.
Add vegetable bouillon into the pot of vegetables and stir well. Pour in water, and add seasonings. Simmer for 15 minutes or so, until vegetables have become tender (fork can go through potato cube with ease.) Add salt and pepper to taste.
Ladle one third or one half of the soup out of the pot, and carefully place in a blender. Put top on blender and blend on low until soup is creamy and pureed. Slowly remove lid (facing away from you so steam does not burn your face), and pour back into pot and stir to recombine with remaining whole vegetables and soup. An immersion blender could also work for this step.
Repeat blending process if you prefer consistency to be more creamy/pureed.