• Heat oil in large saucepan.
• When oil is hot, add onions and cook over medium heat for about 5 minutes until the onions are translucent and some start to brown. Stir frequently.
• Add chopped tomatoes, tomato paste and ginger garlic paste. Cook and stir for another 3 minutes until the tomato paste gets a deep red color.
• Add the turmeric, salt, black pepper, cumin and coriander. Cook for 1 minute stirring frequently. 
• Add about 1/2 cup water and stir to combine all ingredients. You want to make sure the tomato paste is fully incorporated and there are no lumps of it in the sauce. 
• Add another 1/2 cup to 1 cup of water to the saucepan. The consistency of the sauce should be similar to heavy cream or half and half. It should be thick but still easily pourable. Cover and let simmer over medium-low heat for about 15 minutes. Check and stir frequently to make sure the sauce doesn’t get too thick. If it does, add more water so it remains that same consistency. 
• Cook until the tomatoes are completely broken down. 
• Add squash. Stir so that all of the squash is covered in the sauce. Set on medium heat, cover and cook for about 25 minutes. Stir and check on it frequently. The squash is done when it is fork tender. You do not want it to turn into mush.

To Serve

• Pour a thin layer of garlicky Afghan yogurt sauce on the bottom of a large serving platter.
• Add the squash on top of the yogurt sauce.
• Drizzle more yogurt sauce on top of the squash.
• Top with chopped parsley or cilantro.
• Serve with rice, Afghan bread or pita.

Enjoy!