Heat a large non-stick pot over medium heat. Add in a splash of water and saute the onions and garlic until golden in color.
Add celery, carrot, and apple and sauté for another 2-3 minutes. Then add in the curry powder and turmeric powder and stir. Cook for 1-2 minutes more, stirring occasionally. This allows the spices to toast and get fragerant.
Add vegetable broth and salsa and increase heat to medium high. Bring to a low boil. Then add lentils and stir. Once the mixture comes back to a low bubble, reduce heat to low or until you achieve a gentle simmer.
Add in the frozen peas and corn, chickpeas, beans, pre-steamed potatoes and spinach. Simmer the soup uncovered, stirring occasionally, for 12-16 minutes or until the carrots and lentils are tender (red lentils cook pretty quickly, so if you’re using other lentils, adjust cook time as needed).
Once the lentils have finished cooking, take your immersion blender and blend until desired consistency. I prefer a little chunkiness, so I blended until most of the veggies were pureed. If you don't have an immersion blender, you can transfer the soup to a regular blender and blend in batches.
Taste and adjust the flavor as needed. I prefer to add salt per individual bowl but you can certainly add salt to the entire soup.
Divide between serving bowls and garnish with fresh herbs and lemon juice or a little fresh coconut milk or cream (optional). Store cooled leftovers in the refrigerator up to 5 days or in the freezer up to 1 month. Reheat on the stovetop until hot, adding more vegetable broth to thin as needed.