Bring a large pot of water to a boil for the pasta.
Heat a large skillet over medium-high heat with olive oil, 2 turns of the pan. Add bacon and render 2-3 minutes until crispy at edges. Add shallots, garlic, salt, pepper and rosemary, and stir 2-3 minutes. Add stock and cream or crème fraiche then stir in syrup or honey and simmer to thicken sauce. Reduce heat to low and stir in mustard to taste.