Prep the ingredients. Slice the chicken thinly so it cooks quickly and stays tender.
Cut the vegetables into bite-size pieces. Mince the garlic and grate the ginger.
Warm the pan and bloom the curry paste. Heat oil in a large skillet or Dutch oven over medium heat. Add the red curry paste and stir for 1–2 minutes until fragrant.
This step deepens the flavor.
Add aromatics. Stir in garlic and ginger for 30 seconds. Keep the heat moderate so they don’t brown or turn bitter.
Build the sauce. Pour in the coconut milk, stirring to dissolve the paste fully. Add 1/2 cup broth to loosen the sauce.
Bring to a gentle simmer.
Season the base. Add 1 tablespoon fish sauce and 1 teaspoon sugar. Taste later and adjust, but this gives you a balanced starting point.
Cook the chicken. Add the sliced chicken to the simmering sauce. Stir to separate the pieces.
Simmer gently for 6–8 minutes until just cooked through.
Add vegetables that take longer. Stir in carrots and green beans first. Simmer 3–4 minutes.
Add quick-cooking vegetables. Add bell pepper, zucchini, and onion. Simmer another 3–5 minutes, until tender-crisp.
You want vibrant color and a little bite left.
Adjust consistency and seasoning. If the sauce is too thick, add a splash of broth. Taste and add more fish sauce for salt, more sugar for balance, or more curry paste for heat (mix paste with a little hot sauce to avoid clumps).
Finish with freshness. Turn off the heat. Stir in lime juice and a handful of Thai basil or cilantro.
If using kaffir lime leaves, remove them before serving.
Serve. Spoon over jasmine rice or nestle around rice noodles. Garnish with extra herbs and a wedge of lime.