1. Melt the butter, brush onto the sheets of filo dough and put them on top of each other.
2. Cut out round circles of filo dough and place them in muffin cups or similar. The circles should be a little bigger than the bottom of the muffin cups to give the tartlets edges on top. Bake at 350°F for 5-6 minutes until they have a hint of color. Let them cool.
3. Chop the salmon with a knife and combine with the sour cream, mayonnaise, dill and shallots. Season with salt, pepper and lemon zest. Put a small amount of the salmon salad into each tartlet.
4. Top with grated Extra Mature Cheddar and some dill.
If you have any leftovers, the salmon salad is also great on bread.