In a small skillet, heat the oil and onion over medium-high heat for 1 minute. Add the salt and thyme. Lower the heat to medium-low. Cook, stirring occasionally, until the onion is soft and browned, about 15 minutes.
Meanwhile, in a medium heavy pot with a lid, bring the broth to a boil over high heat. Add the kasha and pepper, give it a stir, then lower the heat. When the liquid is gen