In a mixing bowl, combine the ingredients for the steak marinade (soy sauce, olive oil, sriracha, pepper, and lemon juice) and add the steak bites. Mix well and marinate for 15-20 minutes minimum, while preparing the other ingredients.
Heat the olive oil in a large skillet over high heat. Drain steak bites from the marinade. Keep the remaining marinade for later.
Place the steak in the skillet in a single layer. Do not overcrowd the skillet or the meat will steam, so you may have to work in batches depending on the size of your skillet. Cook steak bites for 3-4 minutes, stirring occasionally until steak bites are golden brown. Repeat with remaining steak bites if needed.
Add 2 tablespoons of butter and garlic to the skillet; cook for 1-2 minutes, stirring to coat the meat in the sauce. Remove the steak bites to a shallow plate and set them aside.
In the same skillet, add butter, lemon juice, red pepper flakes, beef broth, and remaining marinade juices. Bring to a simmer and allow to reduce for 2-3 minutes, stirring regularly.
Add the zucchini noodles and toss for 2-3 minutes to cook it up. Stir in the fresh parsley and thyme, then allow the cooking juices to reduce for one minute if the zucchini renders too much water. Push the zucchini noodles on the side, add the steak bites back to the pan and reheat for another minute.