Both - but you may prefer one over the other.
Breakfast consists of a buffet of well-prepared high quality food. It is *mostly* typical breakfast food, though. There are some adventurous accents, but one could dine only on the familiar items and have an excellent breakfast. Highlights for me: cooked to order omelets, grilled tomatoes, unbelievable chocolate pastries with a hint of coconut and coarse sugar melted on top.
Dinner has more of an African accent. There are more adventurous dishes here. Almost all of the dishes are at least African-ish (with the only exception being the kids' station).There are more dishes in general, and much more variety. There are several meat selections at the meat station, with sauces that can be added (or not). There are TONS of side dish options, all of which were unique and delicious. There is a hummus bar. There are always 2 delicious soups. The desserts are varied and interesting. Although the food here is not meat-and-potatoes plain, you will find familiar flavors and most of it seems comforting and homey. My husband loved every meat he tried. I liked everything I had, but I remember the falafel and African pasta salad the most. My daughter ADORED the potato bacon soup.
If we had to pick one, we would pick dinner. On our next trip, we will make it a point to do both, though. It's kind of funny that we liked both meals so much, because we don't typically like buffets.
FYI - I will not eat at Jiko again. We ate there in 07 and then January of 09. Both visits were disappointing, overall. There are high points. The appetizers were delicious both times. We tried dessert the first time and it was to-die-for. My husband liked his entree the first time, but the second time, it was blah. Both entrees that I tried were among the most disappointing entrees I've had on property. They tried to convince me that they intentionally cooked beans "al dente". Hard, chalky beans are not appetizing, no matter what Italian phrase you attach to them. Service this past January was slow and weirdly unconcerned (if that's even a word). Just because you are eating at a fine dining establishment doesn't mean you wish to spend 2.5 + hours there. On the plus side, it's a really spectacular dining room - dark and dreamy. For the $$$, we would rather eat at Flying Fish or California Grill. We prefer Boma to Jiko. Go figure.