1/2 cup unflavored and unsweetened soy or almond milk
1 1/2 tablespoons lemon juice
2 garlic cloves
1 teaspoon salt
1 (10 ounce) package frozen spinach, thawed
1 small onion, chopped
2 tablespoons chopped fresh dill
1 (17.3 ounce package) puff pastry
Preheat the oven to 205 degree celsius and lightly oil 2 standard-size muffin tins.
Place the cashews, milk, lemon juice, garlic, and salt into a food processor and blend until smooth, stopping to scrape down the sides of the bowl as needed.
Drain the spinach and squeeze it to remove as much moisture as possible. Add the spinach to the food processor bowl, along with the onion and dill. Pulse until the ingredients are fully mixed.
Cut each sheet of puff pastry into 3 strips of equal length, and then cut each strip into thirds, making 18 squares. Place each square into the bottom of a muffin cavity, stretching it out just a bit by hand if needed so the corners reach a bit beyond the top of the cavity. Spoon about 2 tablespoons of the spinach mixture into each puff pastry square. Fold the corners of each square inward and pinch then together at the center. Brush the top of each puff with a bit of olive oil.
Bake until the puffs are lightly browned and puffy, about 25 minutes. Remove the tins from the oven and allow them to cool a bit before removing the puffs. Loosen the puffs from the tin by placing a knife down the side, between the puff and the tin.