In a small bowl combine glaze ingredients (a 1 cup glass measure works well). Microwave on HIGH 45 seconds or until preserves are melted, stirring once. Brush glaze evenly over both sides of beef steak.
Thread vegetables alternately onto each of four 12- inch metal or wooden* skewers, arranging zucchini and squash slices lengthwise on skewers.
Combine 1 tbsp mustard and 1 Tbsp oil; brush evenly over vegetables.
Place steak and vegetable skewers on grid over medium coals. Grill 16 to 21 minutes or until steak is medium-rare to medium doneness and vegetables are tender, turning steak and vegetables once.
Trim fat from steak. Carve steak crosswise into slices; season with salt, if desired. Serve beef with vegetables.
*If using wooden skewers, soak in water for at least 15 minutes to prevent from burning.