Preheat oven to 350. Poke potatoes all over with a knife and brush with canola oil. Bake in oven for 1 hour, or until tender and a knife can easily pierce through. Allow potatoes to cool for a bit. Remove the skins and dice into 1/4 to 1/2 in pieces and pass through a potato ricer to create a smooth silkier potato texture. Alternatively, you can hand mash the potatoes for a more rustic, chunky texture.
Over a low heat, heat milk in a small sauce pan, until bubbles begin to form on the sides of the pan.
Over a medium heat, melt butter in a Dutch over or large stockpot. Add the flour a little at a time, whisking to incorporate to create a roux. Cook until lightly brown. Slowly whisk in milk. (i usually transfer the milk to a measuring cup to make it easier to pour slowly) Continue to whisk until slightly thicken, about 2-3 minutes. Add potatoes and green onions.
Bring soup to a boil, allow to simmer for 30 minutes
Serve with bacon, cheese and chives