1. Heat some oil over medium-high heat and fry bacon until crispy. Drain on a paper towel and set aside. 
2. In a bowl over ice, combine beef cubes with olive oil, fleur de sel, and mayo. Add pickles and green onions; then mix to combine.
3. For a lovely presentation, scoop tartare into a cookie cutter to shape on each dish. Press down gently before carefully removing the cookie cutter. Garnish with reserved julienned bacon.

Chef’s secret

Tartare must be eaten fresh on the same day it was made. Add pickles, green onions, and bacon at the very last minute. The beef cube mixture can be prepared a few hours in advance and kept well covered in the fridge.

You can also serve as an appetizer in verrine glasses.