Warm a small skillet over medium-high heat. Toast fennel seeds in skillet until golden brown and fragrant, 1 minute. Remove from skillet to a plate. When seeds are cool, crush with a rolling pin.
In a large, heavy skillet over medium heat, warm oil and bubbles. Add half of ham steaks and cook for 4 minutes on each side, until lightly browned. Remove ham to a plate and cover with foil to keep warm. Repeat with another 1 Tbsp. butter and remaining ham. 1 Tbsp. butter until it melts and
In same skillet, after cooking and removing second batch of ham, melt remaining 1 Tbsp. butter. Add onion and fennel and cook, stirring occasionally, until softened, about 5 minutes. Add wine, broth and cream, along with reserved crushed fennel seeds and both mustards. Bring to a boil, scraping up any browned bits on bottom of skillet, and cook until slightly thickened, about 10 minutes. Season with salt and pepper.
Using a slotted spoon, remove vegetables to a warm platter. Place ham steaks on vegetables and spoon sauce over top. Sprinkle with reserved fennel fronds, if desired, and serve.