Warm 2 tbsp olive oil in a large pot over medium heat. Add diced onion and garlic, cooking until translucent, about 5 minutes, stirring occasionally.

Sprinkle cumin, coriander, smoked paprika, turmeric, and cinnamon over onions. Cook for 1 minute until fragrant, stirring constantly.

Stir in chopped carrots and sweet potatoes, then pour in rinsed brown lentils and vegetable broth. Bring to a gentle simmer, cover, and cook 25–30 minutes.

Use an immersion blender to purée soup directly in the pot until velvety and creamy.

Taste and adjust salt and pepper. Ladle into bowls, garnish with fresh cilantro and yogurt swirl.