Preheat your barbecue. Grill steaks until rare or your preference of desired doneness. Be aware steak is cooked again in oven below. Remove from the grill and slice thinly across the grain. Set aside.
Preheat oven to 425 degrees. Place flat breads on a baking sheet. Brush the bread with a fine layering of olive oil. Top with 6 to 7 slices of plum. Drizzle honey over the top. Divide beef slices between the two pieces of naan. Arrange thin slices of red onion followed by blue cheese crumbles, chopped pistachios, and fresh thyme. Salt and pepper to taste. Place in the oven for approximately 10 -12 minutes, until the blue cheese begins to melt. Serves 3-4.