Drought-friendly vegetable tacos

Wrap the yams in plastic wrap and cook in the microwave on high until soft, about 10 minutes. When cool enough to handle, peel and mash the sweet potatoes.

In a large bowl, combine the flour with the mashed yams, eggs and salt. Using your hands, mix to a uniform, pliable dough — it will be rather sticky. Pinch off about 2 ounces and, with the palms of your hands, roll it to a golf-ball-sized ball. Repeat with the remaining dough and set aside to rest for 45 minutes. You should have about 24 balls.

Form the tortillas using a tortilla press or by hand: Line a sheet pan with parchment and have a few sheets of parchment handy. Generously dust a work surface, your hands, and the rolling pin or tortilla press with flour as you form the tortillas (or use 2 layers of plastic). If rolling, dust each ball with a light coating of flour before rolling. Press or roll each tortilla ball to a 5- to 6-inch disk about 1/16-inch thick. Lay the tortilla disks on the parchment in a single layer and use additional parchment to stack the layers of disks and prevent the tortilla disks from sticking to each other.

Heat a cast-iron skillet over medium heat and brush the surface lightly with 1/4 to 1/2 teaspoon of oil. Add a tortilla disk and toast until the orange had deepened a bit, the outsides are a bit browned and the disk has firmed a bit and starts to ripple and puff from the heat, 35 to 45 seconds. Use tongs to gently flip and repeat on the other side, another 35 to 45 seconds. Repeat with the remaining tortilla disks, brushing the pan with oil after every 3 to 4 tortillas, when it seems to be drying out.

Heat the oven to 450 degrees. In a shallow roasting pan, roast the tomatoes, Serrano chilie and garlic until nicely charred. As the garlic will cook more quickly, check and remove it after about 5 minutes, leaving the tomatoes and chilis for an additional 10 to 12 minutes.

In a large sauté pan over medium heat, toast the guajillo chili, sesame seeds and pumpkin seeds until the sesame seeds are golden, the pumpkin seeds have colored, and guajillo is a bit charred and aromatic, 2 to 3 minutes. Add the roasted tomatoes, chiles and garlic and cook until the vegetables are so soft that they barely hold their shape, about 15 minutes. Season with 1/4 teaspoon salt, or to taste, and transfer to a blender jar or the work bowl of a food processor. Add the vinegar and lime juice and blend to a puree. This makes about 2 3/4 cups of salsa.

Heat the oven to 450 degrees, or prepare a grill. Brush a generous tablespoon of the oil on the green beans, chicory, eggplant and scallions to very lightly coat them. Roast or grill the vegetables until done just beyond al dente, removing the vegetables from the heat as they are done, 8 to 10 minutes for the chicory and green beans, and a few minutes longer for the eggplant. When cool enough to handle, cut the vegetables into bite-sized pieces.

Heat a cast iron pan over medium-low heat and add 2 teaspoons of the oil. When hot, add the cut vegetables, cannellini beans and peas. Stir to combine and add the shallots and garlic. Cook, stirring, until aromatic, 12 to 15 minutes. Remove from heat, stir in the thyme and season with the salt and pepper. Drizzle the sherry vinegar over the top. This makes about 5 cups of filling. Set aside until the tortillas are warm.

In a skillet lightly brushed with oil and heated over medium heat, warm each tortilla and remove to a plate. Top each tortilla with 3 to 4 tablespoons of the vegetable filling, along with a few teaspoons of salsa, or to taste. Garnish with the sliced green onions and sage leaves and serve immediately.