Press tofu for at least 15 minutes to remove excess moisture (wrap in paper towels and place a weight on top). While pressing, wash and trim vegetables: slice onion, carrots, red pepper; cut broccoli into florets; trim snap peas; halve mushrooms; mince garlic and ginger; slice green onions. Measure out sauces and broth; mix cornstarch slurry (1 tsp cornstarch + 1 tsp water) in a small bowl.

Cook tofu (if using)

Heat 1 tablespoon neutral oil in a large nonstick skillet or wok over medium-high heat until shimmering. Add tofu cubes in a single layer and cook without moving 3–4 minutes until golden on the bottom. Turn and cook additional 2–3 minutes to brown other sides. Transfer tofu to a plate and set aside.

Start aromatics and onions

Return the pan to medium-high heat and add the remaining 1 tablespoon oil. Add sliced onion and cook, stirring occasionally, 2–3 minutes until it begins to soften. Add minced garlic and ginger and cook 30–45 seconds until fragrant but not browned.

Add firm vegetables

Add carrots and broccoli florets to the pan. Stir-fry 3–4 minutes until broccoli is bright green and carrots begin to soften.

Add remaining vegetables

Add red bell pepper, snap peas, and mushrooms. Stir constantly 2–3 minutes until vegetables are tender-crisp. If pan looks dry, add 1–2 tablespoons of the broth to help deglaze and create steam.

Build the sauce

In a small bowl combine light soy sauce (3 tbs), oyster sauce (1 tbs), rice vinegar (1 tsp), sesame oil (1 tsp), the remaining broth (if any) or up to 1/2 cup of broth, salt (1/2 tsp) and pepper (1/4 tsp). Stir to combine.

Thicken and finish

Return the browned tofu to the pan. Pour the sauce over the vegetables and tofu. Bring to a simmer for 1 minute, then stir the cornstarch slurry and slowly add to the pan while stirring. Cook 1–2 minutes until sauce thickens and coats the vegetables. Taste and adjust seasoning with additional soy sauce or salt if needed.

Serve

Remove from heat. Spoon steamed rice into bowls (about 1 cup rice per serving). Top rice with the vegetable and tofu stir-fry. Garnish with sliced green onions and toasted sesame seeds. Serve immediately.

Notes

For a gluten-free dish use tamari and a gluten-free oyster substitute. To make this vegan, use a vegetarian oyster sauce or hoisin, and ensure tofu is used for protein. Adjust vegetable mix seasonally (add baby corn, bok choy, or snow peas).