In a large pot heat up the oil, add the bay leaf, garlic, onion and lentils, stir and cook gently for a couple of minutes stirring often.
Add the carrot, sweet potato, pepper, tomato, stir and cook for 2-3 more minutes stirring often. Add the hot vegetable stock, stir, cover and bring to the boil then lower the heat to a simmer and cook, covered, for about 20 minutes.
Remove from the heat, discard the bay leaf and puree the soup. Add a splash of water and adjust the seasoning if necessary and serve.
Notes
Thickness: If the soup is too thick just add a bit more water after you've pureed it.
Seasoning: Do not add any salt until the soup has been pureed (you may not need to add any).
Serving suggestions: Use freshly chopped cilantro/parsley, sunflower or pumpkin seeds to create a bit of contrast, add freshness and crunch to this soup (though it's delicious on its own too). Serve with a knob of butter, dollop of yogurt or splash of cream (if you don't need it to be vegan). Enjoy with croutons.
Storing: Leftovers can be refrigerated for up to 4 days. If the soup thickens add a drop of water.