Try the DISCO supermarket on Rómulo Naon (near Olazábal) in Belgrano R. It's a regular supermarket on the small side, but since it's in a very exclusive neighborhood, they have a very large selection of imported foods from all over the world. The imported stuff is close to the entrance right in front of the vinoteca. Good luck.
We used to shop at Carrefour, but switched to Jumbo in Palermo because they tend to have a better selection of imported goods (and same day delivery). But I agree for special products you may have to look in Chinatown or others shops.
That mosque always looks empty. I know they have a school there, but has anyone ever seen it open? Do many people attend?
I liked Jumbo in Palermo for awhile but I am so tired of the same ol,, same ol'd. Recently I went to the Disco Supermarket just down the street from Starbucks on Elcano. It's a much smaller store but I really liked their selection of food. I was even able to finally find maple syrup.
I make chicken curry with simple ingredients and it turns out really tasty. Chop a whole onion; chop about 6 garlic cloves; chop as much as you like of fresh ginger. Put in a heavy pot and saute in olive oil until soft. Then, add (to taste) approx. 2 Tbsp. cumin, 1 tsp, cinnamon and 1/2 tsp. chili powder, salt and pepper. Mix all together quickly as it will burn if you aren't careful. Add 1 cup of water or chicken broth, mix well. Add 1 small can tomato paste, mix well. Add one cut up chicken (or pieces that you like), cover and simmer for 1 hour. Serve with Basmati rice and chopped cilantro.