Lightly beat eggs with half of the grated cheddar, the peppers and scallions, salt and pepper. Melt butter in a medium skillet over medium heat and lightly scramble egg until just set. Remove pan from heat. Heat tortillas and place two on the counter. Divide the egg mixture evenly between the two, then sprinkle with remaining cheese. Cover with the other tortillas and heat in a non-stick skillet for 3 minutes over medium heat, then turn into wedges and serve with salsa and sour cream.