In a mortar, grind the garlic with turmeric, black pepper, paprika, salt, cumin and red pepper with a pestle. Grind the ginger and squeeze the juice, add it to the mortar with spices. Also add 1/2 cup water. Mix well.
Chop the onion into cubes. In a separate skillet, fry the chopped onions in vegetable oil until transparent.
Add spices from the mortar to the pan, stir. Cook the onion over low heat for 15 minutes.
Put mushrooms and chopped dill in the spices, stir.
Cook for 5 minutes.
Add sour cream to the mushrooms, warm well, but do not let it boil, otherwise the sour cream will curl. Season to taste.
You can serve Indian sauce with oyster mushrooms with porridge or mashed potatoes.