Boil the sweet potatoes: Boil the sweet potatoes in the pot for 20 minutes. The fully boiled sweet potatoes will be soft when you poke them with a fork or a knife. When the sweet potatoes are done boiling, drain the water and add the cooked aromatics to the pot. Add 1 liter of water and the chicken stock cube. Stir to dissolve the chicken stock cube fully, and then use the immersion blender to blend all the ingredients.
Cook the onion, garlic, and spices: Slice the onion, mince the garlic cloves, peel the sweet potatoes, and cut them into 1-inch cubes. Cook the onion for 2 minutes in a preheated pan over medium-low heat with extra-virgin olive oil. Then add the spices and minced garlic cloves, and cook for 1 minute, stirring continuously. When the aromatics are cooked, set them aside.
Add cooking cream: Once the ingredients are blended, add the cream to the pot and cook on medium-low heat for 5 minutes. Stir continuously to infuse the cream and the soup together completely.