I've eaten at Pistachio restaurant mombasa a couple of times recently, it serves decent portions of good simple food at very inexpensive prices.
The Quattro Stagione was very filling for around 300/-, the base was a little thick for my taste and I'm used to the four seasons being laid out as four quarters rather than mixed up, but it was tasty and who can complain at that price?
On my second visit I had the beef curry with vegetable pilau. a decent portion, tender beef and a spicy rather than hot sauce, very tasty and again very inexpensive.
The restaurant is in a tree sheltered courtyard flanked by buildings on two sides and trees on the other. Some tables are in the open, some under makuti roofs.