Soak over night. Drain soaking water and refill with enough fresh water to cover the beans about 1 inch/3 cm. Bring to boil and scoop off the foam that rises. Stop heat and prepare onions and garlic.

Finely chop garlic and onion. Mix together cumin, coriander and red chili/cayenne pepper.

In a separate pot from the beans, heat olive oil and saute onions until softened.

Add garlic and saute for another 1-2 minutes. Next add the cumin spice mix and mix well with onions for another minute or so. Add a little more oil if it becomes too dry.

Pour in the black beans along with the water you cooked it in. Bring to a simmer. Reduce heat to low and cover your pot with a lid.

Simmer for 60-90 minutes until beans soft. Stir the beans occasionally and add a little more water during cooking if needed. You want the soup to be nice and thick in the end, so once the beans start to get soft, remove the lid and boil off excess water until the soup thickens.

To prepare the avocado topping, halve and scoop out the avocado into a bowl. Roughly mash with a fork.

Juice the lime or lemon. Add juice, salt and yogurt to the avocado and mix well. Adjust salt to taste. Also feel free to add more or less yogurt depending on how creamy you want the topping.

When you like the taste, mix in diced tomatoes.

Serve black bean soup into bowls and top with the avocado yogurt topping :) Garnish with fresh cilantro if you have some!