Slice the sausage into medium sized pieces (round pieces); heat 2-3 tbsp oil in a pan and lightly fry the sausages. Keep aside.
In the same pan, heat more vegetable oil (if necessary) and add the sliced onions. Saute for 5 minutes.
Add the ginger, garlic, curry leaves and sauté till the onions are light brown.
Once browned, add the spice powders and sauté for another minute on low heat.
Add the tomatoes and sauté till a mushy consistency is reached.
Add ½ cup water, bring to boil and season with salt. Remember that sausages have salt in it so add accordingly.
Add the sausages and cook on medium heat till done. Garnish with coriander leaves.