6 Tbs. homemade or low-salt chicken broth
1/4 cup ponzu sauce
1 Tbs. toasted sesame oil
1-1/4 lb. boneless beef rib-eye steaks, trimmed and thinly sliced across the grain (1/8 to 1/4 inch thick)
Kosher salt and freshly ground black pepper
3 Tbs. neutral oil, like canola or vegetable
7 to 8 oz. fresh shiitake mushrooms, stems trimmed off, caps thinly sliced
1/2 lb. snow peas, trimmed
3 small or 2 medium scallions (white and green parts), thinly sliced
1-1/2-inch piece fresh ginger, peeled and minced (about 3 Tbs.)
2 medium cloves garlic, minced
In a small bowl, stir the cornstarch into 1 Tbs. of the chicken broth until smooth. Stir in the remaining 5 Tbs. broth, along with the ponzu and sesame oil.
Season the sliced beef with 1/2 tsp. salt and several grinds of pepper. Heat 2 Tbs. of the oil in a large skillet or stir-fry pan over medium-high heat. When the oil is very hot (it should shimmer), add the beef and stir-fry just until it loses its raw color, 2 to 3 minutes. Transfer the beef to a clean bowl. Return the pan to medium-high heat, add the remaining 1 Tbs. oil, and then add the mushrooms and peas. Stir-fry until the mushrooms are tender and the peas are crisp-tender, 4 to 5 minutes. Add the scallions, ginger, and garlic, and stir-fry for 30 seconds. Return the beef to the pan. Give the broth mixture a quick stir to recombine and then pour it into the pan. Cook, stirring, until the sauce thickens, about 1 minute. Serve immediately.
Serve with plenty of steamed white rice.