Grilled Steak and Fingerling Potatoes with Bearnaise Maranade

This was something different for us that was in June's Southern Living.  We loved the salad and have made it again. It's a fabulous summer salad!  You have a lot of leftover dressing and that makes it easy to repeat again that week.  The steak was good too, and the potatoes were so yummy!  They were crispy on the edges and creamy in the middle.  

First, make the Bearnaise vinaigrette:
Whisk together 3/4 cup white wine vinegar; 1/4 cup chopped fresh tarragon; 1/4 cup fresh lemon juice; 3 minced shallots; 2 minced garlic cloves; 1 Tbsp dijon mustard; 2 tsp sugar; 1.5 tsp salt; and 1 tsp black pepper in a bowl until blended.  Add 1/2 cup canola oil and 1/3 cup olive oil, 1 at a time in a slow steady stream, whisking constantly until mixture is smooth.

14 (8-inch) wooden or metal skewers, divided
16 small fingerling potatoes, halved
2 pounds boneless rib-eye, tri-tip, or flank steaks, trimmed and cut into 1 1/2-inch pieces
*I used flank steak
1/4 cup butter, melted
Bearnaise vinaigrette (above), divided
1 cup firmly packed baby arugula
1 cup loosely packed fresh flat-leaf parsley leaves
1/2 cup torn fresh basil
1/4 cup chopped fresh chives
1/4 cup loosely packed fresh mint leaves, torn
3 teaspoons drained capers
Preparation

Soak 8 wooden skewers in water 30 minutes. (Omit if using metal skewers.)  Meanwhile, bring potatoes and water to cover to a boil in a Dutch oven over medium-high heat; cook 10 minutes or just until crisp-tender. Drain.

Combine steak and 1/2 cup vinaigrette in a large zip-top plastic freezer bag. Thread 8 potato halves onto 1 double set of skewers (2 skewers side-by-side), leaving a 1/8-inch space between pieces; repeat with 3 double sets of skewers and remaining potatoes. Cut 4 to 8 crosswise slits 1/4 inch deep on top of each potato. Combine potatoes and 1/2 cup vinaigrette in another large zip-top plastic freezer bag. Seal bags, and chill 3 hours, turning occasionally.  Meanwhile, soak remaining 6 wooden skewers in water 30 minutes. (Omit if using metal skewers.)

Preheat grill to 350° to 400° (medium-high) heat. Remove steak and potatoes from marinades, discarding marinades. Thread steak onto 6 skewers, leaving a 1/8-inch space between pieces. Sprinkle with desired amount of salt and pepper.  Grill potatoes and steak at the same time, covered with grill lid, 6 to 7 minutes on each side or until steak reaches desired degree of doneness and potatoes are golden brown, basting potatoes and steak with melted butter with each turn.

Toss together arugula, next 5 ingredients, and 2 Tbsp. vinaigrette. Serve kabobs with arugula salad and remaining vinaigrette.