In large saucepan combine broth. potatoes, leeks, garlic 1 tsp salt, 1/8 tsp pepper. Bring to a boil over medium high heat. Reduce heat and simmer covered until vegetables are almost tender, about 12 minutes.
Add peas to sauce pan, stir and cook until vegetables are tender about 3 minutes, remove saucepan from heat and let cool for 5 minutes.
Meanwhile in a small bowl whisk together yogart, 2 tbs dill 1/8 tsp pepper until smooth.
Puree soup in saucepan using an immersion blender, stir in remaining tablespoon of dill.
To serve ladle 1 cup soup with into each of 6 small soup bowls. Top each with 4 tsps of yogart mixture swirling mixture into soup. Then top each serving with about 2 tsps of tomato.
1 to 2 minutes cooking time. If you use fresh peas you might have to add 1 to 2 minutes extra.