Article in English: Pour in enough water to cover the seeds. The sunflower seeds will absorb some of the water, which will prevent them from becoming too dry while roasting. Stir to mix in the salt. Leave the sunflower seeds to soak in the salted water overnight. This will help to infuse the sunflower seeds with a salty flavour.   Alternatively, if you are in a rush, you can place the sunflower seeds and salted water into a pot and leave to simmer for an hour and a half to two hours.  If you don't want your sunflower seeds salted, you can skip this step altogether. Pour off the salted water and pat the seeds dry with some paper towel. Spread the sunflower seeds on a baking sheet lined with parchment paper, in a single layer. Try not to have any of the seeds overlapping. Roast the seeds for 30 to 40 minutes, until the shells are golden brown. The shells will also develop a slight crack down the middle as they roast. Stir the seeds occasionally, to ensure that they roast evenly on both sides. The sunflower seeds can be mixed with a teaspoon of butter while still hot and served immediately. Alternatively, you can leave the seeds to cool on the baking sheet, then store in an airtight container.

Summary in Vietnamese:
Cho 1 cốc hạt hướng dương nguyên vỏ vào bát. Thêm 1/3 đến 1/2 cốc muối. Lọc lấy hạt. Làm nóng lò nướng ở nhiệt độ 150ºC. Cho hạt hướng dương vào lò nướng. Thưởng thức và bảo quản.