Heat oven to 350º
Bake potatoes for 1 1/2 hours.
Meanwhile cover bottom of skillet or frying pan with olive oil, add onions to olive oil and saute until tender (about 5 minutes).
Remove onions from heat; drain excess oil.
Add onions to a mixing bowl.
When potatoes are done take out of oven and cut the top 1/4 off of each potato (the long way). Scoop potato out of shell and into mixing bowl with the onions.
Add half & half, butter, salt, pepper and bacon to the mixture.
With mixer combine ingredients until well blended. Add Cheese with a spoon.
Place potato mixture into a medium size plastic bag, twist bag (should appear as a pastry bag).
with scissors clip corner off end of bag.
Squeeze mixture in potato shells, place on cookie sheet and bake another 20 minutes, or until cheese is melted and light brown crust forms on top of the potatoes.