Spinach Tomato Soup with yellow potatoes

2 large potatoes, diced
1 package frozen spinach
1 large can tomatoes
1 T oil
1 large onion, chopped
1 tsp salt
1/2 tsp cinnamon
1/2 tsp cumin
1 tsp turmeric

Cook potatoes in plenty of boiling water until soft. Saute onion in oil until
translucent. Add spinach. Puree tomatoes and add that to the spinach onion
mixture. When spinach is defrosted and broken up, add the potatoes and adjust
the amount of water to be soupy. Add the salt and spices and simmer for half an hour.