In a small saucepan over high heat, reduce the 1 cup sherry vinegar to 1/4 cup. In a mixing bowl, combine the vinegar syrup with 2 tbsp Dijon mustard, 1/4 cup honey, and 1 tbsp ancho chile powder and season to taste with salt and pepper. Let rest 30 minutes. Preheat grill. Brush 4 salmon fillets with the glaze and grill 3 minutes on each side for medium. Serve with the spicy tomato relish. For the Spicy Tomato Relish: Combine 2 medium ripe tomatoes, chopped, 2 tbsp finely diced Spanish onion, 2 tbsp chopped parsley, 1 tsp red pepper flakes, 1/4 cup red wine vinegar,1/4 cup olive oil, salt and freshly ground pepper, to taste in a bowl. Serve at room temperature.