The local "Brochettes" goat kebabs are delicious and are available in most bars and restaurants. Many restaurants also serve grilled fish and chicken, and frites and frites-banane fried plantain are ubiquitous.
In urban areas a local buffet known as "Melange" is sold at lunchtime. This consists of a buffet of mostly carbohydrates such as potatoes, bananas, beans, rice, cassava accompanied by some vegetables and a small amount of meat or fish with sauce.
Note that Rwandan buffets are not all you can eat! You may fill your plate only once, and with practice you'll be able to stack your plate high like some do to make it as close to 'all you can eat' as possible observing the unusual one plate rule. Then of course, the others may shake their heads at you, and give you annoyed stares. Prices run up to USD$10. Most of the buffets offer a salad buffet too. Note that many of the cheaper Melange places don't advertise price, you have to ask.
Many choose to purchase an entree at a restaurant based on the limitations mentioned above, as entrees are hearty more than one plateful and exactly what you want. The reasoning is, why call it a buffet as it is not there in abundance for you? Ask, as there are a few places who observe the worldwide norm for buffets.
Kigali has a much better range of restaurants than the rest of the country. Here you can find several Indian and Chinese restaurants, as well as Italian, Greek, French and multi-cuisine establishments charging around $10 for dinner.