Fry your bacon in a pan until crispy, then remove to a paper towel-lined plate.
In the same pan to utilise the bacon fat, toast the breadcrumbs until golden brown. Now blend the two together until you have a crumb.
Make the anchovy sauce
Place all the ingredients except the parmesan into a jug and blend until smooth. Then add the parmesan and blend again.
Taste the anchovy sauce, and add Worcestershire sauce to your preference, and season with salt and pepper as needed. Add more lemon if it needs brightening, and mix in some room-temperature water to thin it out if it is too much of a paste.
Cook the green beans and assemble
Bring a pot of salted water to the boil and cook the beans in it for 5-7 minutes. You want them to be tender but still have some bite, rather than a crunch. Don't overcook them, or they will go floppy. Drain and set aside.
Toss the hot green beans in the anchovy cream sauce to warm it up, and serve topped with the bacon crumb.
Notes
If you cannot have raw egg yolks, substitute them for 2 tablespoon of mayonnaise. Panko is best for the crunch factor, or you can also blend a bag of croutons. Store leftovers in the fridge and consume within one day. Do not leave out for prolonged periods on the counter.