Bring 4 cups vegetable broth to a boil in a large pot. Slowly whisk in 1 cup polenta, stirring constantly to avoid lumps. Reduce heat to low and simmer for 20-25 minutes, stirring frequently, until creamy and thick. Season with salt and pepper to taste. Keep warm on the back burner.

While polenta cooks, heat 2 tablespoons olive oil in a large skillet over medium-high heat. Add the drained chickpeas and cook for 5-7 minutes, stirring occasionally, until golden and crispy in spots. Transfer to a bowl.

In the same skillet, add 1 tablespoon olive oil. Add the diced onion and cook for 3-4 minutes until softened. Add the minced garlic and cook 30 seconds until fragrant.

Stir in 2 tablespoons tomato paste and cook for 1 minute. Pour in the canned diced tomatoes with their juice. Add 1 teaspoon dried oregano, 1 bay leaf, and 1/4 teaspoon red pepper flakes. Bring to a simmer.

Return the crispy chickpeas to the skillet. Simmer for 8-10 minutes, stirring occasionally, until the sauce thickens slightly and flavors meld. Taste and adjust seasoning with salt and pepper.

Divide warm polenta among bowls and top with the chickpea ragù. Grate parmesan over top if desired. Serve immediately.