Chef and restaurateur Stephanie Izard is on a mission to fight food waste. Together with Morton Salt, Izard, a new mom who won Bravo’s fourth season of “Top Chef,” is working with the campaign to reduce food waste by 50% by 2030.

“It’s to protect our planet,” she said about the campaign. “There’s so many different ways that we can start to try and save the natural resources on this planet, and thinking as a mom, we want to make sure we’re taking every step we can.”

Fifty-two million tons of food go to waste in the US each year – or 40% of the food we buy, according to nonprofit ReFed.com.

The Morton Salt campaign invites people to try a seven-day challenge, which includes doable steps like creating a meal plan, making a shopping list, portioning and freezing foods, and throwing a “leftovers party.”

“I think it’s really important to look at it in a realistic manner,” Izard says. “It’s better to have some goals we can reach so we can start by making small changes that make a huge impact.”

Izard shared some chef-approved tips for reducing food waste.

TIP: Buy whole vegetables instead of prepackaged

Izard says pre-packaged vegetables often spoil much faster than whole vegetables, and recommends buying vegetables you can use when you’re ready to cook and eat them.

The same goes for fruits like avocados and bananaṣ. Izard says she buys avocados depending on when she knows she’ll use them—buying ripe if she’s using it that day, and unripe when using them within four days.

TIP: Find new uses for old bread

Izard says bread is one of our most wasted items, because we often buy more than we can eat. But instead of throwing away bread, take what you think you’ll use and then freeze the rest. Izard says sticking frozen bread in the toaster or putting it on the griddle will liven it back up.

She also recommends taking stale bread and grinding it up to make breadcrumbs, which can be used to coat vegetables and top pastas; cutting and toasting it for croutons; and even putting stale slices through a pasta machine to make homemade crackers.

TIP: Make something new out of leftovers

Izard’s all-time favorite leftover meal is stir-fry, something that can be a catchall for your leftover ingredients.

“If you have leftover rice, it’s perfect, because dried out rice works better for fried rice,” she says. “But if you have leftover meats and vegetables, throw those in, season with a little soy, and I like to add a pat of butter.”

Making something new out of old food will encourage you to eat those leftovers, instead of tossing them in the trash.