6 medium russet potatoes
6 medium sweet potatoes
1/2 cup butter
2/3 cup sour cream, divided
1/3 cup milk
3/4 cup shredded cheddar cheese
4 T. minced chives, divided, fresh or dried
1~1/2 tsp, salt, divided
Wash all of the potatoes with a vegetable brush. Pierce russet and sweet potatoes with a fork. Bake at 400º for 60 to 70 minutes or until tender. Set the sweet potatoes aside. Let potatoes cool a few minutes or till you can handle the potatoes safely. 
Cut a third off the top of each russet potatoes; Scoop out pulp into a bowl; leaving skins intact. Mash with 1/4 cup butter,1/3 cup sour cream, milk, cheese, 2 T. chives and 3/4 tsp. salt. Set a side. 
Cut a third off the top of each sweet potato; scoop out the pulp in a second bowl, leaving skins intact. Mash pulp with remaining butter, sour cream, chives and salt. 
Stuff sweet potato mixture into half of each potato skin; spoon russet potato mixture into other half . Place all 12 half's on a baking sheet. Bake at 350° for 15 to 20 minutes or until heated through.
6 to 8 servings.