Trim and discard large leaves from the bok choy and slice the stalks on the diagonal into half-inch slices. Slice the Napa cabbage crosswise into half-inch strips. Trim and slice the radishes into quarter-inch thick, half-moon shapes. Set aside.
Slice the tofu crosswise into 8 squares. In a large non-stick skillet, heat 1 tablespoon of vegetable oil over high heat. Add the tofu and sear until golden brown on each side.
Reduce to medium heat, add 2 tablespoons of tamari, cook for 1-2 minutes, then flip the tofu and continue cooking until all the tamari is absorbed. Remove and reserve the tofu.
In a medium sauté pan, combine 2 tablespoons toasted sesame oil, seasoned rice wine vinegar, sriracha, 1 tablespoon tamari and brown sugar. Bring the mixture to a boil, whisking to blend in the sugar. Turn off the heat and whisk in the miso paste until smooth. Gently add the tofu to the sauce, flipping once to coat. Let sit.
In a large skillet or wok, heat 1 tablespoon sesame oil; add the bok choy and sauté 3 minutes. Add the radishes, edamame, cabbage, garlic and ginger and sauté 2 minutes. Add 2 tablespoons of water, 3 tablespoons of miso-sriracha sauce and cook, stirring, until the liquid is absorbed.
Divide the bok choy between four plates; top with 2 slices of tofu and divide remaining sauce equally. Serve with a side of rice.
Recipe Notes
The sauce is also delicious on chicken or sauteed vegetables.