In a medium bowl, stir together beef broth, sherry, soy sauce, salt, and pepper. Season meat with curing salt and steak seasoning. Then place it in the bowl with marinade. Cover and refrigerate for 2 to 3 hours.

Heat one tablespoon of oil in a large skillet over medium-high heat. Use tongs or a slotted spoon to transfer venison to the skillet, reserving marinade. Cook and stir until browned and cooked through, 3 to 5 minutes, depending on the size of your pieces. Remove to a clean bowl.

Heat remaining tablespoon of oil in the same skillet over medium-high heat. Add onion and bell pepper strips; cook and stir until starting to become tender, 2 to 3 minutes. Remove them from the pan and place them in the bowl with meat.

Dissolve cornstarch in 2 tablespoons of the reserved marinade. Pour the rest of the marinade into the skillet. Bring to a boil, then simmer over medium heat for a minute. Stir in cornstarch slurry and continue to cook, stirring slowly until thickened, about 1 minute. Return meat and vegetables to the skillet and stir until coated with the sauce. Transfer to a serving dish.