We’ve teamed up with America’s Test Kitchen Kids to delve into the scrumptious science of cooking. You’ve sent in so many great cooking questions that we had to spread the answers over four episodes. This is our first installment: HEAT.

What crazy chemical reactions does heat trigger in food? How do microwave ovens work -- and why can’t you put metal in them when they’re lined with metal? We’ll answer those questions, find out how feeding squirrels helped profoundly change how we prepare food and learn the recipe for a perfect grilled cheese sandwich. Plus: our Moment of Um tackles the question, “How does coffee keep you awake?”

Grilled Cheese
Classic Grilled Cheese Sandwich.
Courtesy of America's Test Kitchen

Recipe: Classic Grilled Cheese Sandwich

This recipe comes from America's Test Kitchen's upcoming The Complete Cookbook for Young Chefs.

Serves 1
Prep Time: 5 minutes
Cook Time: 10 minutes

Prepare Ingredients
2 slices hearty white or wheat sandwich bread
1 tablespoon unsalted butter, melted
½ cup shredded cheddar or Monterey Jack cheese

Gather Cooking Equipment
Cutting board
Pastry brush
10-inch nonstick skillet
Butter knife

1. Place bread slices on cutting board. Use pastry brush to brush melted butter evenly over 1 side of each slice.

2. Flip 1 slice over (buttered side down), sprinkle with cheese, and press down on cheese lightly. Place second slice of bread on top (butter on the outside) and press down gently.

3. Place sandwich in 10-inch nonstick skillet and press it lightly with spatula. Heat skillet over medium-low heat and cook until first side is golden brown, 3 to 5 minutes.

4. Use spatula to flip sandwich over and press lightly again. Cook until second side is golden brown and cheese is melted, about 2 minutes.

5. Turn off heat. Use spatula to transfer sandwich back to cutting board. Let cool for 2 minutes. Cut sandwich in half and serve warm.