Render the bacon in a small pan over medium-low heat, stirring regularly to prevent burning. Drain on paper towels, reserving the fat.
Add the bacon, white beans, vinegar, shallots, nutmeg, anchovies, lemon zest and juice and garlic to a food processor and pulse until mostly smooth. Season with salt and pepper. With the processor running, drizzle in the olive oil and about 1 tablespoon of the reserved bacon fat to emulsify.
Transfer the mixture to a serving bowl and fold in the parsley.