Heat water in a large pot and cook the pasta according to directions. See recipe note #1 regarding different pasta choices. The pasta should cook while you prepare the other ingredients in next step. But watch the timing on the pasta if using gluten-free noodles as they'll be done before you're ready to add them into the cabbage mixture. NOTE: Save about one cup of your pasta water when you drain the noodles!
In a large skillet, heat one tablespoon olive oil over medium high heat. Add sliced mushrooms and saute' until golden, about 5 minutes. If needed, add 1/2 tablespoon butter to help with browning. Add onions and cook, stirring occasionally, until onions are soft, about 3 minutes. Add chopped garlic and cook until fragrant, 30 seconds.
Start with half of the cabbage and stir into the mushroom, onion mixture. Add one tablespoon of the butter and cook until the cabbage begins to brown. See recipe note #2 if wanting to add less oil. Add remaining cabbage and additional tablespoon butter. Add the granulated garlic and onion at this time and continue to cook, stirring until the cabbage has softened and browned around the edges.
Once the noodles are al dente and drained (remember to save some of that pasta water), add the noodles a little at a time until you are happy with the ratio of noodles to cabbage. Add 1 teaspoon salt and 1/4 teaspoon black pepper, less if desired, taste and add more if needed. Add the peas and stir to combine. If you want the dish to be a little "creamy", add some of the pasta water, about 1/4 cup at a time until desired wetness is achieved.
At this point, the recipe is delicious and may be served right out of the skillet. The cabbage and noodles are tasty for sure but to infuse even more flavor, place the mixture into a buttered large casserole dish or roasting pan, add up to 1/2 cup of the pasta water, cover with aluminum foil and bake in a preheated 300F degree oven for 10 minutes, remove the foil and continue to bake 15 minutes more. Baking in the oven helps to tenderize the noodles and cabbage a little more and infuses the onion and garlic flavors into the noodles. I highly recommend the baking step.
Just before serving, whether you serve from the skillet or after baking in the oven, drizzle extra olive oil over the dish and sprinkle with the parsley just before serving. See recipe note # 4 regarding leftovers.