Cook the bacon in a large pot over medium heat, stirring occasionally, until crisp, 5 to 7 minutes; transfer to a plate. Add the shallots to the drippings in the pot and cook, stirring often, until softened, 3 to 5 minutes.
Add as many collard greens to the pot as will fit, season with ½ teaspoon salt and ¼ teaspoon pepper, and cook, tossing frequently and adding more collard greens when there is room, until tender, 12 to 15 minutes. Stir in the lemon juice and sprinkle with the bacon.
This reminds me of the spinach salads from the 80's where we used hot bacon dressing on the greens. Delicious!
