Preheat the oven to 400 degrees. Place the sausage on a foil lined baking sheet and cook in the oven, turning occasionally, to an internal temperature of 155 degrees getting nicely browned all around. Set aside to rest, slice before serving.
In a pot of boiling water cook the pasta according to the instructions on the package. Drain well.
Heat the oil in a saucepot on low heat. Add in the garlic and onion; saute until golden brown. Add in the beans, broth, marjoram, and escarole. Bring to a simmer, stirring occasionally to wilt the escarole. Season with salt and pepper to taste. Continue simmering to build flavor, the sauce should thicken to a creamy consistency from the beans.
Stir the pasta and half of the parmesan cheese into the sauce.
Serve with sliced sausage and bread. Garnish with parmesan cheese and red pepper flakes.