Prepare the slaw and sauce: Place the cabbage in a medium mixing bowl. In a separate large bowl, stir together the Greek yogurt, oil, garlic, and salt. Scoop about half of the yogurt mixture into the bowl with the cabbage. To the cabbage bowl, add the lime zest and juice. Stir to combine, then refrigerate until ready to serve.: The first bowl will carry the crunchy base, and you should notice the fresh vegetal scent when you toss in the shredded cabbage. Work with dry cabbage so the dressing clings instead of diluting; if it seems damp, pat it briefly with a towel. One common mistake is overdressing the slaw early, which makes it limp, so only add half the yogurt mixture now and refrigerate to keep crispness.
To the bowl with the remaining Greek yogurt mixture, add the Thai sweet chili sauce, sriracha, and vinegar. Set aside.: As you whisk the yogurt with the olive oil, the mixture will become glossy and slightly loosened, offering a creamy harbor for the chili sauce later. The minced garlic will release a sharp aroma that mellows after a few minutes; if your garlic is particularly pungent, let it sit in the yogurt to soften. Avoid adding too much salt at once, which is a common error, taste after mixing the other components first.
Prepare the shrimp: Pat the shrimp dry and place in a large ziptop bag. Sprinkle in the cornstarch, then seal the bag and toss the shrimp to coat.: When you spoon the yogurt onto the cabbage, the cabbage will start to glisten and soften just a touch around the edges while retaining crunch in the center. Toss lightly so each strand gets a thin coating. A frequent slip is overmixing which breaks down the cabbage texture, so toss gently until evenly coated.
In a high-sided skillet, wok, or Dutch oven, heat the 3 tablespoons oil over medium high. Once the oil is hot and shimmering, carefully add the shrimp, shaking off as much excess cornstarch as you can. Sauté, stirring almost constantly, until the shrimp is cooked through and the cornstarch is no longer white, about 4 minutes. Do not overcook, and if the shrimp looks dry, drizzle in extra oil as needed. Transfer the shrimp to the bowl with the Greek yogurt/Thai chili mixture and toss to coat the shrimp in the sauce.: The lime zest gives immediate aromatic pops, and the juice will brighten the overall flavor while slightly wilting the cabbage for better mouthfeel. After stirring, set the slaw in the fridge to let flavors meld and for the cabbage to firm up; this resting step deepens the taste. Do not refrigerate too long after dressing, because the slaw can lose its desirable snap.
Warm the tortillas (optional) and assemble the tacos: If you like, warm the tortillas in the microwave (put them in a stack and cover them with a lightly damp towel) or a 250°F oven. To serve, fill the tortillas with your desired number of shrimp and the slaw, then top generously with the slaw and green onions. Enjoy immediately.: Combining the sweet chili with the yogurt base creates a glossy, sweet spicy sauce that will coat the shrimp perfectly. The vinegar heightens brightness while the sriracha supplies controlled heat. Let the sauce sit briefly to allow flavors to integrate; rushing this step can result in a one dimensional sauce.
Pat the shrimp dry and place in a large ziptop bag Sprinkle in the cornstarch then seal the bag and toss the shrimp to coat: Drying the shrimp first is crucial so the cornstarch adheres and creates a light crisp exterior when cooked. The cornstarch will feel powdery at first but will cling evenly if the shrimp are slightly tacky. A typical mistake is skipping the drying step which leads to steaming instead of searing and a softer texture.
In a high sided skillet wok or Dutch oven heat the 3 tablespoons oil over medium high Once the oil is hot and shimmering carefully add the shrimp shaking off as much excess cornstarch as you can: The oil should shimmer and move like silk in the pan, which signals the ideal searing temperature. Adding shrimp that are too wet cools the oil and prevents proper browning, so ensure they are dry. Listen for a lively sizzle on contact; if you do not hear it, raise the heat. Overcrowding the pan is a common mistake that causes steaming, so cook in batches if needed.
Sauté stirring almost constantly until the shrimp is cooked through and the cornstarch is no longer white about 4 minutes: You will see the shrimp turn from translucent to opaque and curl slightly as proteins tighten. The cornstarch will go from chalky to slightly glossy and form a thin crust. Use quick, gentle motions to keep pieces separated and evenly cooked. Do not overcook, which makes shrimp rubbery, and if they look dry, drizzle a little extra oil to maintain juiciness.
Transfer the shrimp to the bowl with the Greek yogurt Thai chili mixture and toss to coat the shrimp in the sauce: When you move the hot shrimp into the sauce, you will hear a soft hiss and see the sauce cling, forming a shiny glaze. Toss gently so each piece gets an even coat without breaking. A pitfall is leaving shrimp in the hot pan too long before saucing which cools the sauce and can change its texture.
Warm the tortillas and assemble the tacos Fill the tortillas with your desired number of shrimp and the slaw then top generously with the slaw and green onions: Warming tortillas releases a toasted aroma and makes them pliable, which prevents tearing during assembly. As you layer, contrast warm and cool elements for the best bite. Overfilling can make tacos fall apart, so arrange components thoughtfully and serve immediately for optimal texture and temperature balance.