1. Gather the onions, broccoli, carrots, and snow peas, then put them in a slow cooker that can hold between 4 and 5 quarts. In a separate bowl, whisk together the stock, scallions, soy sauce, oyster sauce, vinegar, ginger, oil, honey, and garlic. Pour the mixture over the vegetables in the slow cooker and place the lid on. Cook on LOW for 2 to 3 hours, or until the vegetables are tender.
2. As the main dish cooks, bring a pot of water to a boil and cook the pasta until it is al dente, or slightly firm. Follow the instructions on the package for cooking the pasta. Once cooked, drain it.
3. Grab the tofu and set it on paper towels, placing more paper towels on top of it. Press down gently to soak up any excess moisture, then slice it into cubes that are 1/2 inch.
4. Toss the tofu and the cooked linguine into the slow cooker, and stir everything together.