Peppered Beef Sirloin Kebabs with Dijon Cream Sauce

1 tbsp four color mixed peppercorn
1/2 tsp ground cumin
EVOO
2 lbs top sirloin, about 1 1/4 in thick, cut into cubes
2 medium zucchini - cut lengthwise and then crosswise into 1/2 in pieces
2 large bell peppers - cut into 1 1/4 in sqaures

Cream
1/2 cup creme fraiche or Greek yogurt (the recipe actually lists sour cream as an alternative but I think Greek yogurt works better if you can't find creme fraiche)
2 tbsp Dijon mustard
2 tbsp finely chopped chives
1 tbsp red wine vinegar

Prepare the grill for direct cooking over high heat (450-550 degrees).  If using bamboo skewers soak for 30 minutes prior to preparing kebabs
Coarsely grind the peppercorns.  Mix in  1 1/2 tsp salt and cumin.  Place the meat in a large bowl with the spices and add enough oil to coat the cubes lightly; toss to coat evenly.  In another bowl lightly coat the zucchini and bell peppers with oil and season evenly with salt. Thread the skewers alternately with zucchini, meat and bell pepper
In a small bowl whisk the cream ingredients.  Cover and refrigerate until ready to serve
Brush the cooking grates clean.  Grill the kabobs over direct high heat with the lid closed as much as possible, until the veggies are crisp tender and the meat is cooked to your desired doneness - 6 to 8 minutes for medium rare, turning occasionally.  Remove the skewers from the grill and serve warm with the cream

From Weber's Time to Grill cookbook