Sprinkle pheasant with salt and pepper. Melt butter and oil in large skillet over medium heat. Add pheasant; cook 2 minutes on each side or until browned. Add broth and wine; bring to a boil. Cover, reduce heat, and simmer for 35 minutes. Remove pheasant from pan. Keep warm.
Combine milk and cornstarch in a small bowl.
Increase heat to medium-high. Bring broth mixture to a boil; cook until reduced to 1/2 cup (about 6 minutes). Add onion; cook 3 minutes. Add milk mixture and crushed peppercorns. Simmer 2 minutes or until sauce thickens, stirring frequently.