Prepare the dates: Using a small, sharp knife, carefully slice each Medjool date lengthwise along one side, creating a pocket. Be careful not to cut all the way through, so the date remains intact. Gently remove the pit by twisting it out or scooping it with the tip of your knife. Set the pitted dates aside.

Toast the pistachios (optional but recommended): Spread the 150g (1.3 cups) of raw pistachios in a single layer on a baking sheet. Toast them in a preheated oven at 160°C (320°F) for 8-10 minutes, or until fragrant and lightly golden. This step enhances their flavor and aroma. Allow them to cool completely before proceeding.

Process the pistachios: Place the cooled, toasted pistachios into a food processor. Begin processing. The nuts will go through stages: coarse crumbs, then a finer meal, and eventually a paste.

Achieve pistachio butter consistency: Continue processing the pistachios. Scrape down the sides of the food processor bowl periodically with a spatula to ensure even processing. As the nuts release their oils, they will transform into a thick butter. This can take anywhere from 5 to 15 minutes, depending on your food processor's power.

Add oil and salt: Once the pistachio mixture starts to resemble a thick paste, add 1 tablespoon (15ml) of pistachio oil (or your chosen neutral oil) and the 1/8 teaspoon (0.5g) of salt. Continue processing until the pistachio butter is smooth and creamy, similar to peanut butter. If it's too thick, add the remaining 1 tablespoon (15ml) of oil, a little at a time, until your desired consistency is reached.

Taste and adjust: Taste the pistachio butter and adjust seasoning if necessary. Add a tiny pinch more salt if needed to enhance the flavors, or a touch more oil if it's still too stiff.

Stuff the dates: Using a small spoon or a piping bag fitted with a plain tip, carefully fill the pocket of each prepared Medjool date with the homemade pistachio butter. Aim to fill them generously but avoid overstuffing, which can cause the butter to ooze out.

Garnish (optional): If desired, gently press a few chopped pistachios onto the exposed pistachio butter filling of each date for added texture and visual appeal.

Serve or chill: The stuffed dates can be served immediately at room temperature. For a firmer texture and slightly chilled flavor, place them on a plate or in an airtight container and refrigerate for at least 30 minutes (1.5cm / 0.6 inches) before serving.