Prepare the Mushrooms and Snow Peas: Clean and slice the mushrooms if they are large, leaving smaller ones whole. Trim the ends of the snow peas and set both ingredients aside.

Make the Teriyaki Sauce: In a small bowl, whisk together the vegetable broth (or water), tamari, maple syrup, rice vinegar, minced garlic, and freshly grated ginger. In a separate small dish, dissolve the cornstarch in a tablespoon of water to create a slurry. Set both aside.

Cook the Vegetables: Preheat a spacious frying pan or wok over medium-high heat until it's hot. Add the mushrooms and cook, stirring occasionally, for 5-7 minutes until they begin to release their moisture and brown slightly.

Add the Snow Peas: Add the snow peas to the skillet with the mushrooms and cook for an additional 2-3 minutes until the snow peas turn bright green but remain crisp.

Add the Teriyaki Sauce: Pour the teriyaki sauce mixture over the mushrooms and snow peas. Stir to coat the vegetables evenly. Once the sauce starts to bubble, stir in the cornstarch slurry and continue cooking for another 1-2 minutes until the sauce thickens and becomes glossy.

Finish and Serve: Remove the stir-fry from heat. Top with chopped green onions and a dash of sesame seeds, if you like. Serve hot over rice for a complete, oil-free meal.