I havent herd that name "Yeti of Heizen" !!
Sagarmatha is worst restaurant to go; if you wanna have a bad time go there ! Namaste momo is of same owner : look like nepal ko hotel ; fast service too.
Thakali kitchen has best Thali ( Dal bhat tarkari)
Laliguras is good too.
Namaste , lali guras , bhims cafe are like hotel of nepal. Not really restaurant . (Good for short time food like momo sel )
Yak , nepal-japan , woodside cafe , sagarmatha actually restaurant.