Bring broth, 1/2 tsp. salt, and 1 tbsp. oil to a boil in a small saucepan. Add kasha. Cover, reduce heat, and simmer until liquid is absorbed, 10 to 15 minutes. Let stand 5 minutes, then fluff with a fork.
Meanwhile, sauté pancetta in a 12-in. frying pan over medium heat until golden brown and starting to crisp, 5 to 6 minutes. Transfer with a slotted spoon from the pan to a small plate.
Add kale and chile flakes to fat in pan. Cook, stirring often, until kale starts to soften and turn bright green, about 2 minutes. Add lemon zest, 1/4 tsp. salt, the pepper, and a splash of water if pan starts to get dry; cook a couple of minutes more. Stir in kasha mixture and 2 to 3 tbsp. more oil to moisten.
Serve warm or at room temperature, with an egg on each serving if you like, and lemon wedges on the side.
*Find kasha at well-stocked grocery stores and natural-foods stores, and at bobsredmill.com. For the best way to poach eggs, go to sunset.com/poachedeggs.