Peel and cube the russet potatoes, place them in a large pot of salted water, and bring to a boil. Cook for about 10 minutes or until fork-tender. Drain and set aside.

Add chopped cabbage and onions to the boiling water and cook for 5 minutes until softened. Drain and let cool.

Return the drained potatoes to the pot and mash until creamy. Mix in shredded cheddar cheese until melted and smooth.

Lay out flour tortillas and spread Thousand Island dressing on one half of each.

Layer creamy mashed potatoes, slices of corned beef, and the cooked cabbage and onions on the dressed side of each tortilla. Fold in half.

Heat vegetable oil in a skillet over medium heat. Fry each taco for about 30 seconds on each side until golden brown.

Remove from skillet and place on a paper towel-lined plate. Garnish with chopped chives and serve warm.