Sure, Meatless Monday may be a trendy slogan, but it recycles an old idea.

I was reminded of America’s long history of dietary restrictions as I toured City Hall in Philadelphia. In a corridor by the Conservation Room, I spotted a black-and-white photo proclaiming: “Food Will Win The War. Don’t Waste It.”

During World War I, the U.S. Food Administration urged families to reduce consumption of key nutrients to bolster the war efforts. The government instituted what became known as “Meatless Monday” and “Wheatless Wednesday.”

The campaign was reinstated during World War II. President Harry Truman continued the program after the war as a way to help feed Europeans who were hungry and had little to eat. The campaign was retrofitted in 2003 to encourage average Americans to curb their meat consumption for better health.

Why choose Monday as the day to go meatless? We often do our healthiest eating at the beginning of the week, experts say.

The Kansas City Star’s Rustic Cheese Baked Polenta With Mushrooms is a tasty meatless and wheat-free dish that offers home cooks an opportunity to explore new ingredients and flavor combinations. Add a crisp green salad to serve as a side dish brunch — or dinner on Monday, or any day of the week.

Rustic Cheese Baked Polenta with Mushrooms

Makes 6 main-dish servings or 10 side-dish servings

4 cups water

1 teaspoon salt

1 cup coarse- or medium-grind cornmeal

2 tablespoons olive oil, divided

1/2 teaspoon dried thyme

7 tablespoons shredded Parmesan cheese, divided

8 ounces button mushrooms, sliced

4 ounces oyster mushrooms, sliced

4 ounces shitake mushrooms, sliced

Salt and pepper, to taste

3 ounces fontina cheese, shredded (about ¾ cup)

Preheat oven to 350 degrees. Spray an 8-inch square baking dish with nonstick cooking spray; set aside.

In a medium saucepan over medium-high heat, bring water and salt to a boil. Add the cornmeal in a slow, steady stream, whisking during this process. Whisk in 1 tablespoon olive oil and thyme. Reduce heat to maintain a simmer, and cook, stirring frequently until mixture is very thick, about 15 to 20 minutes. Stir in 3 tablespoons Parmesan cheese.

Meanwhile, heat remaining 1 tablespoon olive oil in a large nonstick skillet, over medium-high heat. Add the mushrooms and cook, stirring frequently until the liquid boils away and the mushrooms are golden. Add salt and pepper to taste.

Place half the polenta mixture into the prepared 8-inch baking dish. Sprinkle with 2 tablespoons Parmesan and half of the shredded fontina cheese. Scatter half the mushrooms evenly over all. Continue layering with the remaining polenta mixture, Parmesan, fontina and mushrooms.

Bake, uncovered, 15 to 20 minutes until cheese is bubbling and mixture is hot through and beginning to crisp on the sides. Serve immediately.

Per serving, based on 6: 287 calories (34 percent from fat), 11 g total fat (4 g saturated), 21 mg cholesterol, 36 g carbohydrates, 11 g protein, 578 mg sodium, 5 g dietary fiber.

Recipe developed exclusively for The Star by professional home economists Kathy Moore and Roxanne Wyss.