Sweet Potatoes in glaze

In anticipation of Thanksgiving and Christmas:

4 medium sweet potatoes
1 c. sugar
dash of salt
3/4 c. real butter pieces
2 slices of lemon twisted over and laid on top (or some dashes of lemon juice)
1 Tbsp. flour
1/4 c. water

Skin potatoes, cut into chunks. Combine all ingredients in 9x13 baking dish. Bake at 400 degrees for 1 hour, basting frequently.