Bring a large pot of salted water to a boil and cook egg noodles according to package directions until al dente. Drain noodles and set aside.
Add 1/2 cup of butter to a large dutch oven or deep pot over medium heat and cook until melted. Slice the onion and add to the butter. Cook, stirring occasionally, until onions are translucent, about 5-10 minutes.
Add the remaining 1/4 cup of butter to the pot and melt.
Chop the cabbage into bite-sized pieces and add to the pot.
Cook, stirring often, for 5-10 minutes or until cabbage has softened. Add the garlic and cook for 30 seconds more.
Stir the cooked egg noodles into the cabbage mixture. Season well with salt and pepper.
Transfer to a 9x13 buttered baking dish and bake at 300 degrees for 30 minutes or until the top is golden brown.