Although I am not a fan of foreign cuisines while traveling, I was convinced by my better half and was more than happy to have eaten here.
As we were traveling with our 9 month old the owner immediately gave us a bigger table and even took time to introduce himself, play with our daughter and share his and our stories.
I love spicy food and even in India I had to repeatedly ask for "non-tourist spicy" but "loca-spicy". At Mendi, the owner asked me level 1, 2 or 3 of spiciness and I chose 3, which was superbly spicy, yet enough to taste the delicious mutton curry. My fiancee had a very delicious palak paneer and we shared a tandoori kabab.
Yes, it is a higher priced restaurant for Porto or Portugal in general, but as a reviewer before me said "great quality has its price".