Melt half the butter in a large, heavy-based frying pan and cook the scallops and bacon over a high heat, stirring frequently, for 2 minutes until just golden and cooked through. Remove with a slotted spoon and keep warm.
Add the remaining butter to the pan and cook the leeks over a medium heat, stirring occasionally, for 5 minutes until softened and lightly browned in places. Add the crème fraîche and lemon rind and season generously with pepper.
Return the scallops to the pan and toss into the creamy leeks. Serve immediately with quick-cook rice.