Cook the rice according to package instructions; keep warm.
Place the cubed chicken and 2 teaspoons ground coriander into a large resealable bag; seal and shake to coat the chicken evenly, then set aside.
Heat the olive oil in a very large wok or large frying pan over medium-high heat.
Add the remaining 2 teaspoons ground coriander and the minced ginger to the hot oil; stir and cook 30 seconds to 1 minute until fragrant.
Add the coated chicken to the pan and cook until lightly golden and cooked through, about 3–5 minutes per side depending on pieces' size.
Reduce heat to medium and add the chopped portobello mushrooms, chopped red bell pepper, and the bok choy stalks; cook until vegetables are tender, about 3–4 minutes.
Stir in the bok choy leaves, chicken broth (1/2 cup plus 2 tablespoons), coconut aminos, coconut sugar, and 1 teaspoon sriracha (if using). Bring to a boil and cook 1 minute to dissolve the sugar and meld flavors.
Divide the cooked rice among 4 plates. Spoon the chicken and vegetable mixture over the rice, distributing the sauce evenly so it soaks into the rice.
Garnish each serving with lime wedges, chopped Thai basil, toasted sesame seeds, and extra sriracha if desired; serve immediately.