Heat olive oil in a large pot over medium heat. Add diced onion and cook until soft, about 5 minutes. Stir in garlic and cook for another minute until fragrant.

Add diced potatoes, carrots, and celery. Stir to coat with the onion mixture.

Pour in the vegetable broth. Add thyme, smoked paprika, salt, and pepper. Bring to a boil, then reduce to a simmer. Cover and cook for about 20 minutes or until potatoes and carrots are fork-tender.

Use an immersion blender to partially blend the soup in the pot for a creamy yet chunky texture. (Or blend half of the soup in a regular blender and return to the pot.)

Add plant milk, nutritional yeast (if using), and lemon juice. Heat through for another 5 minutes. Taste and adjust seasonings.

Ladle into bowls and garnish with chopped green onions, chives, or red pepper flakes.