First, season your room temp steaks with salt and lots of cracked black pepper. Grill or pan fry up to your desired temperature (I recommend medium to medium-rare). Be sure to baste with some of the butter to keep it moist. Set aside and let rest.
Preheat the oven to 350. Slice the baguette at a bit of an angle in about 1/2 inch slices and arrange on a baking sheet. Bake for a few minutes on each side until they are crusty but not too dried out. Allow to cool.
While the crostini bake, mix together the spicy brown and dijon mustard. Once they have cooled, spread a small amount of the mustard mixture on each slice of bread.
Slice the rested steaks into about 1/4 inch slices. Place one slice on top of each crostini.
Top with fresh snipped chives and serve! Enjoy!
