Process peppers, walnuts, oil, lemon juice, cumin, kosher salt, and garlic in a food processor until smooth, about 30 seconds. (Be sure not to overprocess or you'll have a gloppy mess. It should be smooth but still have a small bit of texture.)
Unfold the pastry sheet on a clean work surface, and then press seams with fingertips to smooth them out. Spread the red-pepper mixture over the pastry, leaving a ¼-inch border, and then fold in half toward you, pressing the borders with your fingertips to seal.
Place the pastry on a small baking sheet and transfer it to the refrigerator for 15 minutes.
Meanwhile, preheat the oven to 400°F. Line baking sheet with parchment paper or silicone mat.
Transfer the chilled pastry packet to a cutting board and, with longest side facing you, use a sharp knife to cut 8 (½-inch wide) strips. Pinch the short ends of each strip and twist. Tie the strip into a loose knot, tuck in its ends, and place on the prepared baking sheet.
Brush knots with melted vegan butter and then sprinkle generously with dried oregano, sesame seeds, and flaky sea salt. Bake, rotating the baking sheet halfway through, until golden brown, 25 to 30 minutes. Let cool for 5 minutes. Serve warm or at room temperature. Enjoy!