Bring the beef stock to a boil in a medium saucepan over medium-high heat. Immediately lower to a simmer and cook until reduced to 1/2 cup, about 45 minutes. Set aside.
Preheat a grill to medium-high heat. Sprinkle the strip steaks with the salt and pepper and let sit for 15 minutes.
Place the steaks on the grill, evenly spaced, and grill for 2 1/2 minutes; rotate a quarter turn and cook another 2 1/2 minutes¿this creates cross-hatch sear marks. Flip the steaks and repeat on the reverse side. Remove steaks to a baking sheet and let rest for 4 to 5 minutes.
Combine 2 tablespoons of the butter, the shallots and the five-peppercorn blend in a medium saucepan over medium heat. Cook until the shallots and peppercorns are fragrant and the butter is beginning to bubble. Off the heat, add the brandy and the red wine. Carefully place the saucepan back on the burner and allow the brandy and wine to flame. Add the reduced beef stock and the heavy whipping cream, bring to a boil and immediately lower to a simmer. Cook until the liquid has reduced by two-thirds, about 8 to 10 minutes. Prior to serving, whisk the remaining 2 tablespoons butter into the sauce, then remove from the heat.
With a sharp knife, slice the steaks 1/2-inch thick on the bias. Transfer to a large serving platter and spoon over the five-peppercorn sauce. Garnish with the minced parsley. Serve immediately.
Use extreme caution when igniting alcohol. Remove the pan from the heat source before adding the alcohol. Pour the alcohol into the pan and carefully ignite with a match or click lighter. Return the pan to the heat and gently swirl to reduce the flames.