This is perfection.
Seriously, it DOES NOT GET ANY BETTER than this.

This is what you need:
Sourdough bread – toasted (don't even flirt with the idea of using any other kind)
Thomy mayonnaise – on both sides of the toast (don't scrimp and get Kraft, it won't be the same)
Mixed lettuce leaves (avoid those bitter purple leaves)
Thickly sliced tomatoes – two to three slices
Sea salt
Cracked black pepper (and lots of it)
Crispy, fresh bacon.

If you do not have an amazing day after eating one of these then you cannot be helped.
This goes for vegetarians too.

I recommend being mildly hungover and eating it in bed. Joy.