In a large heavy pot, heat 2 tablespoons of olive oil or butter over medium heat. Add 2 cups of finely chopped leeks or onions and sauté for 4 to 5 minutes until softened.

Stir in 2 cups of diced carrots and 2 cups of chopped celery, cooking for another 5 minutes.

Add in 3 cloves of minced garlic and cook for about 30 seconds until fragrant.

Mix in 4 cups of diced Yukon Gold potatoes along with 1 cup of optional pearl barley.

Pour in about 6 to 7 cups of vegetable or chicken broth, adding 1 bay leaf and fresh thyme. Stir gently and bring to a gentle boil.

Reduce heat to low and let the soup simmer uncovered for 30 to 40 minutes.

Check the liquid level and add more broth if necessary. Mash some softened potatoes for a thicker texture.

Remove the bay leaf and thyme sprigs, and season with salt and pepper to taste.

Ladle into bowls, garnish with freshly chopped parsley, and serve hot.