To make the dressing: Combine the oil, vinegar, sugar, and soy sauce in a jar and shake until the sugar has dissolved.
Melt the butter in a large skillet over medium heat. While the butter is melting, crush the ramen noodles while still inside the package. Remove the seasoning packet and throw away (or set aside for later use). Add the noodles, almonds, and sesame seeds to the melted butter in the skillet.
Saute while stirring frequently, until the noodle mixture is golden brown. Remove to a plate and let cool.
Shred the cabbage and combine the cabbage and onions in a large mixing bowl. Add the noodle mixture. Pour the dressing over the salad and toss well to combine. Serve immediately.
This is not a make-ahead salad. I like to make the dressing in advance and then add the noodles and dressing to the cabbage right before serving. I will happily eat any leftovers, but the noodles will be softer and for what it's worth, it isn't quite as lovely as when freshly made.<br>The original directions for the dressing were as follows: Combine the oil, vinegar, sugar, and soy sauce in a medium saucepan. Stir and bring to a boil. Remove from the heat after boiling. Let the dressing cool completely before pouring it over the salad.