Pulse the roasted salted pistachios in a food processor until finely ground. Add olive oil and blend to achieve a thick, creamy pistachio paste.

In a large mixing bowl, cream together softened salted butter and both sugars until light and fluffy, about 3-4 minutes. Add egg and vanilla, mixing well.

In a separate bowl, whisk together the flour, matcha powder, baking soda, and salt until fully combined. Gradually fold into wet ingredients, being careful not to overmix.

Gently fold in the dark chocolate chunks until evenly dispersed. Your cookie dough should be soft and sticky.

Cover bowl with plastic wrap and refrigerate the dough for at least 2 hours.

Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper. Using a cookie scoop, portion out chilled dough onto the sheet, spacing 2 inches apart. Bake for 10-12 minutes until edges are golden.

Let cookies cool on the baking sheet for 1 minute, then transfer to a wire rack. Optionally, sprinkle with flaky sea salt while warm.