Prepare broccoli florets. Peel and slice carrot. Slice button mushrooms into thin slices. Chop up garlic cloves.
Heat up some olive oil in a wok. When hot, pour out excess oil from wok. (I don't like my food oily, so I do this; but it's optional.).
Fry 1/2 of the chopped garlic until fragrant. Add carrots and stir-fry, making sure heat is evenly spread. After about a minute, add broccoli florets. Stir-fry for a few minutes, until broccoli begins to darken, and then add the mushrooms and continue stir-frying for about a minute.
Turn heat down and add 1/2 cup water to the wok. Add 1 tbsp soy sauce and 1 tbsp mirin sauce. Continue stir-frying for a couple of minutes.
Turn the stove off and cover the wok with a lid to make sure it remains warm.
Prepare another wok by heating up some olive oil. Pour out any excess oil.
Fry the rest of the garlic until fragrant. Add the spaghetti and stir-fry, making sure to mix well.
Add 2 tbsp soy sauce (or to taste) and mix well. Turn heat down a little bit and add 1/4 cup water. Continue stir-frying for a few minutes before turning your stove off.
Pour spaghetti and the spaghetti's 'sauce' into a plate. Add the vegetable stir-fry on top, making sure that the vegetable stir fry's sauce is also added inches.