For best results, add yogurt into a bowl and whip for about 5 minutes with a hand mixer. Add the crumbled Feta and and olive oil, mix until smooth. Adjust flavouring (more Feta or yogurt).
From the half head of lettuce, remove the core and cut into two equal wedges place on plates.
Top each wedge with diced tomatoes and shrimp. Spoon over whipped Feta on each portion, garnish with chives, fresh ground pepper and serve.