Bring a large pot of salted water to a boil. Add the pasta and cook as the label directs; drain and rinse under cold water. Transfer to a large bowl.
Add the steak, bell pepper, green beans and bacon to the bowl with the pasta.
Make the dressing: Mix the mayonnaise, sour cream, lemon juice, garlic, parmesan, and salt and pepper to taste in a bowl. Pour over the pasta salad and toss to coat. Season with salt and pepper. Chill for up to 3 hours.