Rinse 1 cup rice about 4 times or until water runs almost clear; drain well and cook rice according to package instructions with 1 Tbsp butter and 1/2 tsp salt. You can also use a rice maker. Once it's cooked, remove from heat and set aside.
Finely slice the cabbage (a mandolin is the fastest way to slice cabbage)
Fine dice the onion and grate the carrot.
Heat a large, heavy bottomed skillet or a Wok over very high heat. Add 2 Tbsp cooking oil then toss in the sliced cabbage, carrot and onion. Sauté over very high heat for 7-10 minutes until cabbage is wilted and starting to turn a little golden. Stir constantly so it doesn't scorch to the bottom of the pan. The veggies will shrink down to about 1/3 or 1/2 of their original size.
Add in 2 Tbsp butter and 3 cups cooked rice. Stir to combine. Add 2 Tbsp soy sauce, 1 tsp sesame oil, plus salt and pepper to taste (I didn't use salt and sprinkled in 1/8 tsp pepper). Stir well to combine and serve.
Notes
*Or 1 cup uncooked Jasmine rice with 1 Tbsp unsalted butter and 1/2 tsp salt