Spread walnuts out on a baking tray and bake for 8-10 minutes until lightly toasted.Tip: If you're using a toaster oven, you can place the walnuts in the oven without preheating and toast for 11-13 minutes.
Add toasted walnuts to a food processor and blend until smooth and runny. It will clump together at first but should turn smooth within a few minutes. Keep blending until the walnut butter is thin and drippy, not like a thick peanut butter.
Transfer to a jar and let the walnut butter cool, then store in the fridge.