Place onions in a skillet with a lid over medium heat. Cook, covered for 10 minutes or until very dry, stirring occasionally.
Add chicken fat (butter or margarine) to onions and raise heat to medium high. Cook, stirring occasionally, until well-browned. Place onions in a separate bowl.
Add kasaha to slightly beaten egg. Stir to coat every grain of the kasha. Then add kasha to the same skillet and stir with a fork over high heat until it is dry and toasted. Break apart the grains. This will take about 3 minutes.
Add the chicken stock or water, salt and pepper. Bring to a boil. Add onions. Cover and cook over low heat for 10 minutes until kasha is tender and the liquid is absorbed. If not ready, cover and cook about 4 more minutes.
Add kasha to cooked and drained bowtie pasta. Season with more salt and pepper to taste.