I went here a while back with high hopes based on the reviews I had read and was so disappointed :(
The service was abysmal. The lady serving ice cream was incredibly impatient with me as I attempted to choose what flavor I wanted... even though I was the only customer in the restaurant and it was the middle of the day. After I asked to taste a flavor (I saw the little tasting spoons so assumed this was a fair request), she abruptly stated I could only taste 3 before I had tasted any at all. That's fine; it's obviously not exceptional customer service to so adamantly limit the amount flavors new (or any) customers can try but I understand that they may have had their reasons for doing so. What really put me off was her attitude and how openly unhelpful she was being.
All that aside, I dealt with the discomfort of ordering from her and got a single scoop of ice cream. I wish I could remember what flavor(I want to say guava?), but the texture was so bad I couldn't even eat it! It was grainy and tasted artificial. Maybe it contained real guava, but definitely not fresh ones.
Based on the many positive reviews El Oasis has received, I hope that my poor experience was a unique incident. However, I personally cannot recommend it.