Combine poppy seeds and mustard seeds in a small bowl, cover with cold water and soak overnight or for a day.
When you are ready to start cooking, drain the water from the poppy-mustard seed mixture. Wash and cut the zucchinis into small cubes.
Add 1/4 cup water in a blender and run it at a high speed. Slowly add the soaked poppy and mustard seeds in the running mixer using a teaspoon. Run the blender for a minute or so after adding all the poppy and mustard seeds until it becomes a thick paste.
Pour the oil in a large frying pan and heat on medium high. When the oil is hot put the onion seeds in the pan and after about five seconds add the cubed zucchini. Fry the zucchini in medium heat for about five minutes and then pour the poppy and mustard seed paste on the zucchini. Add the salt and turmeric. Mix using a large spoon.
Put the lid on the frying pan and cook for another five to seven minutes. Add a little bit of water if the mix gets too dry during the cooking. The preparation should be moist but not runny. Remove from heat and serve hot with rice.