For Vinaigrette: Combine all ingredients, adding Jalapeno to taste. Let sit at room temperature approximately 4 hours to let flavors blend.
:Split each lobster and clean, keeping meat in the shell. Season salt and freshly ground pepper. Marinate lobsters in olive oil and grapefruit juice for one hour. Drain and discard marinade. Grill lobsters over hot coals or preheated gas grill for approximately 5 minutes. DO NOT OVERCOOK. Remove lobster meat from shells, rough chop and place in martini glasses. Top with vinaigrette and garnish with swizzle stick of lemongrass or leaf of radicchio.
Optional Modifications: Sprinkle 2 Tbs. of flavored (orange, cranberry or lemon) or plain vodka over each martini.