In a large pot, heat 2 tablespoons of sesame oil over medium heat. Add one diced onion and sauté for about 5 minutes until it becomes soft and translucent.

Stir in 4 minced garlic cloves, 1 tablespoon of grated ginger, 1 teaspoon of ground cumin, 1 teaspoon of ground coriander, and ½ teaspoon of crushed red pepper flakes. Cook for an additional 2 minutes.

Add 1 cup of rinsed red lentils and 4 sliced carrots to the pot, mixing well. Stir everything together for about 1-2 minutes.

Pour in 4 cups of vegetable broth and bring to a boil. Reduce heat, cover, and let simmer for 25-30 minutes.

Allow the soup to cool slightly before blending until smooth. Use an immersion blender or transfer to a standard blender in batches.

Stir in 2 tablespoons of soy sauce and 1 tablespoon of rice vinegar. Season with salt and pepper to taste, then reheat gently.

Ladle the soup into bowls and garnish each serving with toasted sesame seeds, fresh cilantro, and a lime wedge.