Place a small skillet over medium-high heat. Add the fennel seed and toast, tossing frequently, for about 7 minutes.
Remove from heat to a plate and allow to cool. Once cooled, grind the fennel seeds to powder.
Place the fennel powder in a bowl with the olive oil, mustard, maple syrup, salt and pepper. Whisk the sauce until smooth.
Place a skillet in the oven and preheat the oven to 375F.
When the oven comes to temperature, spray the hot pan with the olive oil and place the steaks in the pan. Cook for about 5 minutes, then turn and cook for another 5 minutes (for medium-rare).
Remove the pan from the oven and set the steaks on plates for serving.
Add the beer to the pan. Place the pan over medium high heat and whisk the beer into the remaining sauce for about 45 seconds.
Serve the steak topped with the sauce.