Heat 1 teaspoon of the oil in a nonstick Dutch oven over medium-high heat. Add the chicken; sprinkle with the salt and cook, turning occasionally, until browned, about 6 minutes. Transfer the chicken to a bowl; set aside.

Add remaining 1 teaspoon oil to the same Dutch oven, then add the onion, carrots, and celery. Cook, stirring occasionally, until the vegetables begin to soften and brown slightly, about 6 minutes. Add the broth and potato; bring to a boil. Reduce the heat and simmer, covered, until the potato is almost tender, about 10 minutes. Add green beans and cook until crisp-tender, about 6 minutes. Stir in the browned chicken and the peas; heat through, about 2 minutes.

Meanwhile, to prepare the dumplings, combine the baking mix, milk, sage, and pepper in a bowl until a soft dough forms.

Drop the dough, by rounded tablespoons, onto the simmering stew, making a total of 6 dumplings. Simmer, uncovered, 10 minutes. Then cover and simmer until the dumplings have doubled in size and are cooked through, about 10 minutes longer. Yields 1 cup stew with 1 dumpling per serving.