Heat a large heavy-bottomed pot over medium heat. Add the extra-virgin olive oil and warm for 30 seconds. Add the diced onion, carrot, and celery and sauté, stirring occasionally, until the vegetables are softened and the onion is translucent, about 6–8 minutes.

add garlic and tomato paste

Add the minced garlic and tomato paste to the softened vegetables and cook, stirring constantly, for 1–2 minutes until fragrant and the tomato paste darkens slightly.

toast barley briefly

Add the rinsed pearl barley to the pot and stir to coat with the oil and tomato mixture. Toast the barley for 1–2 minutes to develop a nutty aroma.

add liquids and tomatoes

Pour in the vegetable broth and the canned diced tomatoes with their juices. Stir well to combine, scraping up any bits from the bottom of the pot. Add the bay leaf.

Seasoning & Simmer

Stir in the dried oregano, dried thyme, sea salt, and black pepper. Bring the soup to a gentle boil over medium-high heat, then reduce heat to low to maintain a simmer. Cover partially and simmer until the barley is tender but still slightly chewy, about 30–35 minutes. Stir occasionally to prevent sticking; add up to 1/2 cup water or broth if soup thickens too much.

Beans & Greens

When the barley is nearly tender (about 25–30 minutes into the simmer), add the drained and rinsed beans to the pot and stir. Continue simmering until the barley reaches desired tenderness and the beans are heated through, about 5–10 more minutes.

Stir in the chopped baby spinach in batches, allowing it to wilt into the hot soup. Taste and adjust seasoning, adding more salt or pepper if needed.

Finish & Serve

Remove and discard the bay leaf. Stir in the fresh lemon juice to brighten flavors. If you prefer a creamier texture, use an immersion blender to gently puree 1–2 cups of the soup and then stir back into the pot (optional).

Ladle the soup into bowls and sprinkle with grated Parmesan cheese if using. Serve hot with crusty bread.