Prep everything ahead of time as the actual cooking part goes fast. Add the sauce ingredients to a bowl and whisk until combined.
Add 1 tablespoon of the olive oil to a large skillet over medium-high heat. Let the pan heat up for a few minutes (the oil should be shimmering).
Add the broccoli and cook for 4-5 minutes, tossing/stirring often (it'll be tender-crisp). Transfer it to a plate.
Add the remaining 1 tablespoon of olive oil to the skillet, then add the beef and cook it until browned and cooked through, breaking it up with your spoon as you go along (about 5 minutes). If there's lots of excess fat, spoon some out.
Reduce the heat to medium, then add the broccoli back to the pan and pour the sauce in. Stir/toss until coated and the sauce has thickened (about 1-3 minutes). Take the skillet off the heat and serve immediately.
