In a pot of salted boiling water; cook the broccoli rabe until tender, about 3-4 minutes. Drain and cool under cold water. Pat dry on paper towels and then chop. In a large skillet, toast steel cut oats over medium heat for 5 minutes until fragrant and nutty, stirring constantly. Add vegetable broth and bring to a boil. Reduce heat to low and simmer, stirring occasionally until oats have thickened, about 20 minutes. While oats are cooking, heat 1 tablespoon olive oil in a skillet. Add sausage and cook until lightly browned. Add another tablespoon olive oil, garlic and red pepper and cook for 1 minute. Add broccoli rabe and cook until tender, about 3-4 minutes. Combine the sausage and broccoli rabe with oats and mix to combine. Divide among bowls and top with Parmesan.