Slice strawberries and mix with blueberries. Sprinkle with tablespoon of sugar. Cover and refrigerate for at least few hours or overnight.
To make biscuits, combine flour, baking powder, salt, and sugar. Cut in butter with two knives. Add egg and milk, and stir until combined. Mix in about two shakes of nutmeg and lemon rind to taste. Pat out to 1" thick and cut 3" circles.
Place on baking sheet and bake at 450 for about 15 minutes. Allow biscuits to cool slice in half through equator. Spoon berry mixture over bottom halves, and add fresh whipped cream. Top with remaining half.