Heat oil in a large pot over medium heat. Add chopped onions, minced garlic, and grated ginger, cooking until onions are translucent.

Stir in diced tomatoes, chopped carrots, and diced potatoes. Cook for a few minutes until vegetables start to soften.

Add dried lentils, vegetable stock, and a blend of Indian spices (turmeric, cumin, coriander, and garam masala). Bring to a boil.

Reduce heat to simmer. Cover and cook until lentils and vegetables are tender, about 30 minutes.

Optionally, use an immersion blender to partially blend the soup for a thicker consistency.

Stir in chopped spinach or kale until wilted. Season with salt and pepper to taste.

Serve hot, garnished with fresh cilantro and a squeeze of lemon juice.