Place stir bourbon, soy sauce, maple syrup, rice vinegar, ginger and garlic into a small saucepan and place over medium heat. Stir everything to incorporate and bring to a simmer. Lower heat and allow to simmer, stirring occasionally, until the alcohol has cooked off (taste test), about 10 minutes. Stir cornstarch and water together in a small cup or bowl and add to whiskey mixture. Allow to simmer 1 minute more, until sauce thickens a bit. Remove from heat.

Coat the bottom of a large skillet generously with oil and place over medium heat. Working in batches if needed, roll tofu cubes in cornstarch mixture and transfer to skillet in a single layer. Cook until crispy on bottoms, about 3 minutes. Flip and continue cooking on each side until crispy (it's okay if you miss a side or two on some of the cubes). Add oil to skillet as needed between batches and continue until all tofu cubes are cooked, transferring each batch to a paper towel-lined plate when done.

Coat skillet with another tablespoon of oil and raise heat to high. Add cauliflower and white parts of scallions. Stir-fry until cauliflower is tender-crisp and browned in spots, about 5 minutes.

Lower heat and add tofu back to skillet, along with whiskey sauce. Cook just until sauce becomes bubbly and coats cauliflower and tofu, about 1 minute.

Divide rice or quinoa onto plates and top with stir-fry. Sprinkle with green parts of scallions, peanuts and red pepper flakes, if desired. Serve.