Gumbo z'Herbes/Vegetarian Gumbo

This adaptation from New Orleans chef, Leah Chase, eliminates the meat and uses smoked paprika to add depth to the flavor.

3 pounds mixed greens such as mustard greens, collards, turnip greens, beet greens, radish leaves, watercress, kale, parsley and others, washed, tough stems removed, and chopped into 1-inch pieces (can be prepared ahead - see note below)
8 cups vegetable broth
Water as needed
1/2 cup vegetable oil
1/2 cup all purpose flour or white rice flour as a gluten free alternative
1 large onion, finely chopped (2 cups)
1 medium green bell pepper, seeded and finely chopped (1 cup)
1 medium red bell pepper, seeded and finely chopped (1 cup)
3 ribs celery, finely chopped (1 cup)
6 cloves garlic, finely chopped
1 to 2 teaspoons ground cayenne pepper
2 teaspoons smoked spanish paprika
1 teaspoon dried thyme
2 teaspoons fine sea salt plus more as needed
1 teaspoon freshly ground black pepper plus more as needed
12 cups cooked white or brown rice
Scallion tops coarsely chopped, for garnish

Place the greens and the broth in a large pot; add enough water to cover the greens. Bring to a boil over high heat, then reduce the heat to medium or medium-low so the liquid is barely bubbling. Cook the greens until very tender, about 40 minutes. Remove from the heat.
While the greens are cooking, make a roux: Heat the oil in a heavy pot over medium heat. Once the oil shimmers, whisk in the flour until smooth. Reduce the heat to medium-low; cook, stirring constantly, until the mixture turns a light brown color, 10 to 20 minutes.
Stir in the onion, green and red bell peppers, celery, garlic, cayenne pepper, smoked paprika, salt and pepper. Cover, and cook, stirring occasionally, until the vegetables are very tender, about 20 minutes.
Drain the cooked greens, reserving the liquid. Transfer the greens to the pot of vegetables. Measure the reserved cooking liquid and add 8 cups of it to the pot. Increase the heat to bring it to a boil, then reduce the heat until the liquid is barely bubbling. Cook for 10 minutes, just to incorporate all the flavors. Taste, and add salt and pepper as needed.
Divide the rice among serving bowls, and ladle a cup of hot gumbo over each portion. Garnish with the scallions.

Adapted from "Greens: A Savor the South Cookbook," by Thomas Head (University of North Carolina Press, 2016).

Make Ahead: The cooked greens and their broth can be refrigerated for up to 5 days before you make the gumbo.

The finished gumbo can be refrigerated for up to 1 week or frozen for up to 3 months. Makes about 13 cups.