1. Mix the yeast and milk. Let it rest at room temperature for 5 minutes.
2. Make a well with the flour and place the salt and eggs in the middle.
3. Mix well, gradually adding the milk/yeast mixture.
4. Set aside for 4 hours.
5. Cook each blini in a small buttered pan, no larger than 12 cm.
6. Preheat the oven to 180°C (350°F).
7. Place a slice of goat cheese on the bottom blinis.
8. Add a slice of smoked salmon.
9. Cover each croque with a blini.
10. Place the croque-blinis on a baking sheet lined with parchment paper.
11. Bake for about 10 minutes, until the cheese is melted. Cover with aluminum foil if cooking too quickly.
12. Remove the croque-blinis from the oven and place small piles of salmon roe on each one. Serve with lemon wedges and garnish with a few sprigs of chives.