For the wasabi cream: Combine the sour cream, mayonnaise, cilantro, heavy cream, wasabi, garlic and salt and pepper to taste in a bowl. Chill for 2 hours.
For the petite filet: Preheat the oven to 425 degrees F.
Heat a cast-iron skillet over medium-high heat until hot. Drizzle the steaks with olive oil and season with salt and pepper. Add the steaks to the skillet and sear quickly, about 1 minute per side. Transfer the skillet to the oven and roast for 5 minutes.