On a griddle over medium heat, cook bacon until crisp, 8 to 10 minutes, turning once.
Drain on paper towels.
Pour off fat; reserve.
In a large bowl, whisk together flour, sugar, salt, baking powder, baking soda and chives. In a blender, mix buttermilk, butter and 1 cup peas.
Add egg; pulse to combine. Fold buttermilk mixture into dry ingredients until just combined. Fold in remaining 1/2 cup peas. If batter is too thick, stir in 1 Tbsp. milk.
Rewarm griddle over medium heat; grease with 2 tsp. reserved bacon fat. Working in batches, drop 1/4 cupfuls of batter onto griddle. Cook until undersides of pancakes are golden, about 2 minutes. Flip pancakes with spatula and cook 2 minutes more. Repeat with remaining batter.
Serve pancakes with reserved bacon and sour cream and more chives, if desired.