Add oil to skillet over high heat. When oil is hot add the cold rice and butter. Stir until butter melts and all of the rice has been coated. Add pepper and drizzle of sesame oil. Continue to cook over med-high heat and stir occasionally. (Here is where I would add veggies if you want them.) After about 5-8 minutes add soy sauce turn the heat down and mix well. Cook for another few minutes to heat through.
I sample the rice throughout the cooking process to make sure it isn't getting crispy and that I have seasoned it enough. You may need to adjust your heat if your rice starts to get crunchy.
If you do not have leftover rice, you can cook some up and put it on a baking sheet and place in the freezer for about 10-20 minutes -- works great!