Combine the ground peppercorns and salt and liberally coat the bison steaks.
In a heavy-bottomed saucepan on medium-high heat melt the butter with the oil and sugar. Add the shallots and caramelize them for 10 minutes. Add the wine, turn down the heat to a simmer and reduce liquid to 1/4 of its original amount. Remove from heat. Add thyme and season.
On a hot grill, cook the steaks to the desired doneness.
To serve, top each of the steaks with a spoonful of the shallot marmalade. The marmalade can be hot, warm or room temperature.