Vegan Sesame Yaki Udon Noodles

Prepare the vegan seitan beef strips according to this recipe or prepare the baked tofu according to this recipe. This can be done a day or two in advance.
1 recipe TYBM's Homemade Vegan Seitan Beef, OR 1 recipe TYBM's Flavorful Baked Tofu
In a large skillet or wok, heat a teaspoon of sesame oil. Sauté the yellow onion until translucent, about 5 minutes.
1 tsp sesame oil or neutral oil, 1 medium yellow onion
Add the chopped broccolini and add 2-3 tbsp water. Cook for 6-8 minutes until softened and the water is dissolved.
2-3 cups chopped broccolini or broccoli
While the broccolini is cooking, mix all of the sauce ingredients together except for the cornstarch. In a separate small bowl, mix 2 tbsp of the prepared sauce with the cornstarch to form a slurry. Set aside.
1 tbsp toasted sesame oil, 1 tbsp rice vinegar, 3 cloves minced garlic, ½ tbsp minced ginger, 2 tbsp agave nectar or maple syrup, 1-2 tsp sambal oelek or sriracha, 4 tbsp soy sauce or dark soy sauce, 2 tbsp water, 1 tbsp cornstarch
Add the udon noodles to the pan with the onion and broccolini. Cover for 2-3 mins to loosen the noodles. Add ½ the sauce to the pan. Toss until the noodles are coated.
15 oz package vegan udon noodles
Add the prepared “beef” strips or tofu and the remainder of the sauce plus the cornstarch mixture.
Heat for 3-4 more minutes until the sauce thickens and everything is evenly coated. Serve immediately and top with cilantro, green onion, and sesame seeds.