Heat the vegetable oil in a large skillet over medium-high heat. Add the cubed meatloaf and cook for 3 to 4 minutes, stirring occasionally, until the edges begin to brown.
Stir in the minced garlic and cook for 30 seconds until fragrant.
Add the frozen mixed vegetables and cook for 2 minutes, stirring often, until they start to soften.
Push the mixture to one side of the skillet. Pour the beaten eggs into the empty side and scramble until just set.
Add the day-old cooked rice and break up any clumps with a spatula. Stir everything together.
Pour in the low-sodium soy sauce and mix well to coat the rice and other ingredients evenly.
Remove the skillet from the heat and stir in the sliced scallions.