Cut collard greens into bite-size pieces. Bring a large pot of salted water to a boil over high. Add collards, and cook, stirring occasionally, until bright green and just softened, 3 to 4 minutes. Drain and rinse with cold water. Squeeze to release any excess liquid.
Cook chopped bacon in a large skillet over medium-high, stirring often, until crisp, about 10 minutes. Transfer cooked bacon to a paper towel-lined plate. Reserve 2 tablespoons drippings in skillet.
Add yellow onion to skillet, and cook, stirring often, until tender, about 5 minutes. Stir in flour, and cook, stirring constantly, until toasted, about 1 minute. Gradually stir in cream and chicken broth. Bring to a boil over medium-high, stirring constantly. Stir in collards and half of the cooked bacon (about ⅓ cup), and reduce heat to medium-low. Simmer, stirring often, until collards are tender and liquid is reduced, about 15 minutes. Stir in salt and pepper. Top with remaining cooked bacon, and serve.
