In a medium bowl, use a fork to thoroughly mash the sardines. Add the olive oil and mash to combine.
Pour in the lemon juice, add the butter, then season with salt, pepper, and paprika. Mix well to combine the flavors and obtain a paste.
Fold in the chopped shallots until evenly distributed throughout the mixture. Taste the pate and adjust the seasoning to your liking.
Transfer the pate to a jar and refrigerate for at least an hour to allow the flavors to meld together.
When ready to serve, you can sprinkle smoked sea salt flakes and an extra pinch of paprika over the top for a burst of flavor and color.