Line a baking sheet with paper towels.
Add the oil to a large skillet or wok set over medium-high heat. Once the oil is hot (See Kelly’s Notes), fry the green beans in batches, tossing frequently, just until they begin to wrinkle, about 2 minutes. Using a slotted spoon, transfer the cooked beans to the baking sheet and repeat the frying process with the remaining green beans, returning the oil to the correct temperature in between each batch.
Carefully pour the hot oil our of the skillet into a large bowl and let it cool completely before discarding.
In a small bowl, whisk together the mushroom bouillon with 2 tablespoons hot water and the soy sauce until combined. Set the mixture aside.
Return the skillet to medium-high heat and add 1 tablespoon vegetable oil along with the garlic and mushroom bouillon mixture. Stir constantly for 1 minute then return the green beans to the skillet and toss to combine. Serve warm.