Heat 2 tablespoons of olive oil in a large pot over medium-high heat. Add diced onion and sauté for about 3 minutes until translucent. Stir in minced garlic, dried thyme, and sea salt; cook for another minute.

Pour in 4 cups of vegetable broth and add grated potato. Cover and bring to a boil, then simmer for about 10 minutes until the potato is soft. Stir in frozen peas and cook for 2-3 minutes until bright green.

Remove from heat, stir in baby spinach (if using), and blend with an immersion blender until creamy. Adjust seasoning with black pepper to taste before serving.