Slice bacon into thin strips. Add to large skillet and turn to medium heat. Fry until bacon is cooked but not browning.
Chop onion, celery and carrot. Add to bacon mixture and sauté until softening. Add garlic and cook slightly.
Add cooked rice and spread evenly on bottom of the pan. Let sit for 15-20 seconds or so, stir, then spread out again. Repeat until rice has combined well with vegetable mixture and is starting to dry out.
Add soy sauce and stir well to combine, continuing to fry as above.
Rinse and drain frozen peas. Add to rice mixture and stir to combine.
Whisk egg slightly in bowl. Move rice to outer edge of pan and pour in egg. Stir to scramble slightly, then stir into the rice mixture, continuing to stir fry until egg is cooked through.
Taste and season with salt if necessary.
Garnish with green onion or chives if desired.