What practice involves cooking with foods that are often considered waste, such as ugly fruits and leftovers?

The correct answer is upcycling, which refers to the process of repurposing food items that might otherwise go to waste, such as blemished or oddly shaped fruits and leftover ingredients. This practice not only minimizes food waste but also reduces the environmental footprint associated with producing new food. By using these undervalued ingredients creatively, restaurants can create new dishes that appeal to customers while promoting sustainability.

Upcycling is distinct from other options like recycling, which typically refers to processing materials to create new products, or composting, which involves transforming organic waste into a nutrient-rich material for soil enhancement. Downcycling refers to converting objects into materials of lesser quality, which is not the goal when it comes to culinary practices aimed at minimizing waste. Upcycling focuses on maximizing the utility of food that is still safe and nutritious.