A few decades ago when I was in my teens and still living at home with the parents, both of our local utilities (SoCal Edison and SoCal Gas) encouraged customers to skip preheating their ovens for recipes with baking times of 30 minutes or more. I've been doing that ever since with excellent results and have added an extra step, especially when cooking meats and poultry: leave the food in the oven for an additional 15 minutes, i.e.: cooking on stored heat.
We have a Hotpoint gas stove with a self-cleaning oven/broiler so heat loss is not a major problem. The oven also lacks a fast preheat cycle which would light both burners and probably scorch the top of the food on a cold start. Similarly, most fast-preheat ovens have a way to disable the feature.
If you want to give it a try, here's a no-boil version of my Baked Chili Cheese Mac recipe.
2 15-oz. cans chili (with or without beans as desired)
2 chili cans of water
1 lb. uncooked elbow macaroni
1 lb. shredded Cheddar cheese
Spray your 5-quart Corning Ware Pyroceram or Visions Dutch oven with non-stick cooking spray.
Combine chili, water and macaroni in a large mixing bowl. Stir together for about a minute to make sure every elbow is saturated inside and out. Fold in the cheese.
Dump the mixture into the prepared Dutch oven, poking any errant elbows below the surface. Don't worry about the soupy consistency.
Set the Dutch oven on the middle rack and bake uncovered from a cold start for 1 hour. Leave in the oven an additional 15 minutes, then remove and let stand at room temperature for 15 more minutes.
Total cooking time is comparable to par-boiling the macaroni first.
Shovel into bowl, admire, then DIG IN!
