Hearty Lentil Potato Soup (One-Pot Comfort)

Ingredients

• 2 tablespoons olive oil
• 1 medium yellow onion, diced
• 2 medium carrots, diced
• 2 celery ribs, diced
• 4 cloves garlic, minced
• 2 tablespoons tomato paste
• 1 teaspoon ground cumin
• 1 teaspoon smoked paprika
• 1 teaspoon dried thyme
• 1 1/2 cups (300 g) brown or green lentils, picked over and rinsed
• 1 1/2 lb (680 g) Yukon gold potatoes, cut into 1/2-inch cubes
• 1 can (14.5 oz / 411 g) diced tomatoes with juices
• 6 cups (1.4 L) vegetable broth, plus more as needed
• 1 bay leaf
• 1 1/4 teaspoons kosher salt, plus more to taste
• 1/2 teaspoon black pepper
• 1 tablespoon fresh lemon juice, plus more to taste
• 1/4 cup chopped fresh parsley
• Olive oil, for serving (optional)