| 1 | Combine oil, lemon juice and pepper in shallow dish. |
| 2 | Swirl chicken in mixture to coat. |
| 3 | Cover with plastic wrap and marinade in frig 30 minutes. |
| 4 | Meanwhile combine vinegar and wine in heavy small sauce pan and boil over medium high heat until liquid is reduced to about 2 tablespoons. |
| 5 | Remove from heat and add tarragon and pepper. |
| 6 | Whisk in butter on tablespoon at a time blending thoroughly after each addition. |
| 7 | Place over low heat and continue whisking until sauce has thickened slightly. |
| 8 | Whisk in mustard. |
| 9 | Set aside and keep warm. |
| 10 | Prepare charcoal grill. |
| 11 | Drain chicken well. |
| 12 | Grill three to four minutes on each side. |
| 13 | Arrange on heated platter. |
| 14 | Garnish with lemon slices and parsley. |
| 15 | Serve warm sauce separately |
