Toast walnuts in a small skillet, over medium-high heat for 2-4 minutes. Move walnuts around as they toast so they don't burn. Once they become a little darker in color and fragrant, remove from heat and place onto a cutting board. Allow walnuts to cool for 8-10 minutes. Chop into smaller pieces.
Combine softened butter and walnuts with remaining ingredients. Scoop mixture out onto a large piece of plastic wrap or parchment paper. Using wrap (or paper) as a guide, roll butter into a log shape. It's very important that it's even and that the middle isn't larger than the tips. Twist ends, tuck under and place into refrigerator for 2-3 hours before using.
To use, simply unroll butter and cut off a 1/2" sized pieces and place onto top of steaks, prime rib, or chops.
Store mixture in an airtight container in the refrigerator for 1-2 weeks.
*Change it up. Use toasted pecans, hazelnuts, or even roasted chestnuts instead of walnuts in the butter. Pecans and chestnuts are great flavor additions to pork and poultry, while hazelnuts offer a nice nuttiness to vegetables.