Process them on high. Stop 3-4 times to scrape the sides with a spatula and allow the food processor to rest. Process until smooth and creamy, for 10-15 minutes.
If using, now is the time to add the sea salt, honey, and coconut oil. Process until smooth and fully incorporated, for 1 more minute.
Use immediately, or store in the fridge, in an airtight container, for up to four weeks.
Video
Notes
If you'd like to toast the walnuts before processing them, preheat your oven to 350°F. Spread the walnuts on a rimmed baking sheet. Toast until fragrant, 8-10 minutes. Allow them to slightly cool. The raw version is creamier, while the toasted version is more flavorful.
The nutrition info assumes that salt, honey, and coconut oil were added. The nutrition for 2 tablespoons (32 grams) of the butter with no additions is basically the nutrition info for 32 grams of raw walnuts: Calories 208, Fat 21 g, Saturated Fat 2 g, Sodium 1 mg, Carbs 4 g, Fiber 2 g, Sugars 1 g, Protein 5 g.
Although the raw butter is very good without any additions, its flavor is very mild - almost bland. So, if you want a more pronounced flavor, I recommend toasting the walnuts and using the optional ingredients - salt, honey, and coconut oil.
You can keep this nut butter in an airtight container in the fridge for up to four weeks. You can also freeze it for up to four months. Because of its high fat content, it won't freeze completely, but the freezer temperature will help it stay fresh for longer.