If using frozen udon, you have two options: microwave for 2-3 minutes, flipping halfway, or boil until defrosted and drain. For fresh or shelf-stable udon, cook according to the package instructions.
Heat a large nonstick pan over medium-high heat. Add the vegan beef patty and cook, breaking it into smaller pieces, for 3-4 minutes or until golden brown. Remove from pan and set it aside.
In the same pan, add olive oil. Sauté carrots, mushrooms, snow peas, and garlic for about 5 minutes or until crisp-tender.
Return the cooked vegan beef to the pan. Add thawed udon noodles and pour in teriyaki sauce. Stir until everything is evenly coated and heated through.
Transfer the mixture to a serving plate and garnish with green onions and sesame seeds. Enjoy!