To make the green beans, set a large skillet over medium heat. When hot, add 2 tablespoons sunflower seed oil and the panko. Cook, stirring continually, until panko turns a pale golden hue (2 - 3 minutes). Quickly add a pinch each salt and black pepper, and 1/4 cup Parmesan, cooking just until it sizzles and melts a bit (about 1 minute). Scrape into a bowl. Let the skillet cool a bit and wipe it clean.
Set the same skillet over medium heat; let it get nice and hot. Add 1 tablespoon sunflower seed oil, and then the green beans. Nudge green beans as they cook, working them into a single layer. Sprinkle with salt. Adjust heat as needed – the pan should be hot with just a little smoke. Continue cooking and nudging until green beans are tender and seared on all sides, about 8 minutes total. In the last minute, toss green beans with garlic, pepper flakes, black pepper, and the remaining 1/4 cup Parmesan, and cook for 1 minute. The cheese will sizzle and melt just a bit as it cooks.