Cook potatoes in boiling water, until just tender. Drain and set aside to cool a little. Make a white sauce by melting the butter in a small saucepan over medium heat and mixing in the flour. Mix in well the milk, and stir until it thickens. Add seasonings and cheese, stir until cheese melts. Add hot dogs and peas and carrots, mix well. Add cooled potatoes and mix gently. Pour into a 1 1/2 quart casserole dish and bake uncovered at 350 degrees oven for 45 minutes or until heated through. serves 6 to 8