Heat the olive oil in a large saucepan set over medium heat. Add the onion and garlic and cook until slightly softened, golden and fragrant, about 2 minutes.
Add the lentils and spices, stir well and continue cooking for about a minute, then throw in the sweet potatoes, vegetable broth, water and apple juice; bring to a simmer, cover and cook until the lentils are tender but still have a bit of a bite to them, about 25 to 30 minutes. Add a little bit more water if you ever find it necessary.
When the lentils are cooked to your liking, combine the tomato paste, peanut butter, maple syrup, lime zest and lime juice as well as the grated ginger in a small bowl or measuring cup. Whisk until well combined and stir that right into the soup.
Kill the heat and reduce the soup to a thick puree with the help of a stick blender.
Delicately stir in a cup and a half to two cups of almond milk (or other non-dairy milk of your choice), until the soup reaches the desired consistency. Bring back to a quick simmer and then serve without delay.
Garnish with a dollop of sour cream or plain yogurt, slice of lime, fresh parsley, a drizzle of olive oil and a pinch of freshly ground pepper, if desired.