Add butter to a medium sauté pan on medium heat. When foam has subsided, add shallots and peppercorns. Cook until shallots are golden brown, about 5 minutes. Add brandy, and cook until liquid is reduced by half. Add stock and cream, and cook until liquid has thickened, about 5 minutes. Season with salt.

Strain liquid through a fine-mesh sieve, pressing on shallots and peppercorns to release remaining liquid.