Beef and Vegetable Stir-Fry

Steps

1. Prepare the vegetables: Cut the zucchini, removing the seeds and tearing it into jagged pieces. Slice the bell peppers (yellow and red) down the center, scoop out the inside, remove any ribs, and cut them into similar shapes to the zucchini.
2. Cut the broccoli into longer pieces for a nice sear.
3. Prepare the aromatics: Julienne half of the onion and crush 4-5 garlic cloves.
4. Marinate the beef: In a bowl, toss the top sirloin with 1 teaspoon of baking soda and 2-3 tablespoons of soy sauce or tamari. Add a couple of pieces of crushed garlic to the marinade.
5. Heat the pan: Place a carbon steel pan over high heat and add beef tallow until it is smoking hot.
6. Cook the onions and zucchini: Add the sliced onions first, cooking them down slightly (about 1-2 minutes). Then, add the zucchini and cook until tender but not mushy. Remove both from the pan and set aside in a bowl.
7. Add garlic and mushrooms: Add more beef tallow to the pan if needed. Add the crushed garlic and sauté briefly until fragrant. Add the oyster mushrooms; let them release their liquid and evaporate before proceeding.
8. Sear peppers and broccoli: Add more beef tallow to the pan. Sear the bell peppers and broccoli in batches, cooking until they are charred on the exterior but still retain some crunch (al dente). Remove both from the pan and set aside with the other vegetables.
9. Cook the beef: Return the pan to high heat. Add the marinated top sirloin in batches and sear it thoroughly on all sides. Once cooked through, remove the meat and add it back into the bowl with the vegetables.
10. Prepare the sauce: In the same pan, add fish sauce, oyster sauce, and champagne vinegar. Let this mixture cook briefly to concentrate the flavors.
11. Thicken the sauce: Whisk together a cornstarch slurry (cornstarch mixed with water) and pour it into the simmering liquid while stirring constantly until the sauce thickens and becomes velvety.
12. Combine and finish: Pour the thickened sauce over the meat and vegetables in the pan. Fold in half of the chopped water chestnuts. Toss everything gently to coat evenly, then remove from heat.