Heat the oil in a large skillet over medium-low heat. Once hot, add the garlic and beef. Cook the ground beef for 3 - 4 minutes, breaking it up with a spatula.
While the beef is cooking, prepare your vegetables. For the broccoli, cut the florets off the broccoli head and cut them into small pieces. For the carrots, slice into thin, half-rounds. For the pepper, remove the seeds and core and thinly slice. For the scallions, finely chop the white and green parts. Set all the vegetables aside.
Once the beef is almost cooked through, add the sauce, broccoli, carrots, and pepper. Cook for another 2- 3 minutes before adding the noodles.
Create a well in the center of the pan where you can lay the noodles. Pour the broth on top, starting with 2 cups of liquid. The noodles should be partially covered, but don't need to be fully submerged.
Cover and cook for 2 - 3 minutes until the noodles are al dente. Add the scallions and toss everything together. If you want it to be a bit more saucy, add some more broth until you've reached your desired consistency.