Heat sesame oil in a wok or large, deep skillet over medium heat. Add the garlic and cook just until it becomes fragrant, 1 to 2 minutes.
Add beef and cook about three minutes on each side, just until it develops a little bit of color.
Add the peppers and broccoli to the pan and cook over medium-high heat for 5 minutes, stirring frequently.
In a small bowl, whisk together the aminos, peanut butter, rice wine vinegar, and lime juice.
Add the sauce to the pan and stir to combine everything evenly. Cook for about 5 minutes, stirring frequently to ensure the sauce is evenly distributed.
Evenly divide into meal prep containers. Top with chopped cilantro and chili flakes, if desired.