Sprinkle both sides of steak with black pepper, press firmly into meat. Salt to taste and set aside.
To prepare sauce, heat 2 tbs of oil in saucepan. Cook pink and green peppercorns and shallots till shallots are wilted but not browned. Remove pan from heat, then add cognac or brandy. Return pan to heat, ignite cognac with a match and cook until the flame goes out. Add broth and cook until mixture is reduced by half. Add cream and continue cooking, stirring constantly, until mixture is thick enough to coat the back of the spoon. Season to taste with salt and pepper and set aside to keep warm.
With burner on high, heat skillet until very hot. Then add enough of remaining oil to cover bottom of the pan. Add steaks, searing just until nicely browned. Turn steaks and cook approximately 2 minutes longer for medium rare. Pour sauce over steak and serve immediately with white rice or mashed potatoes.