Decide how you’re using boursin (cold spread/dip vs. warm sauce or pasta mix-in).
Choose the closest substitute from the table by texture first (spreadability vs. melt behavior).
Measure using the listed ratio, then stir in herbs/garlic and add a small pinch of salt to match boursin’s savory depth.
If your substitute is wetter (like blended yogurt), strain or simmer very briefly to thicken before serving or mixing.
Taste and fine-tune: add lemon zest for brightness, or extra herbs for the signature boursin vibe.