Make the Dough: In a medium mixing bowl, combine flour, salt, and yeast. Add 1 ¼ cups of warm water and stir. If the dough feels dry, stream in the remaining ¼ cup. If the dough still seems dry, add more water 1 tablespoon at a time. Mix with a spatula until a shaggy dough forms, being careful not to overmix (no kneading necessary). Brush the top and sides of the dough with olive oil (helps to prevent the dough from drying out). Cover the bowl tightly and let rise at room temperature until doubled, about 2 - 4 hours.TIP: If your kitchen is chilly, place the bowl in the oven with the light turned on (but the heat OFF) to encourage rising. Make the roasted onions: Preheat your oven to 400°F. Slice the onion into thick wedges (about 6–8 wedges per onion) and place on a rimmed baking sheet. Drizzle with 1 tablespoon olive oil, vinegar, and a pinch of salt. Toss gently to coat, spreading the wedges out in an even layer. Roast on the center rack for 20–25 minutes, or until very soft with lightly browned, caramelized edges. Set aside until ready to use.
Brown the sausage: Heat a large skillet over medium heat. Add the sausage and cook, breaking it up with a spatula, until browned and crispy around the edges, about 6–8 minutes. Remove the sausage with a slotted spoon and set aside, leaving a bit of the rendered fat in the pan.
Sauté the chard: If the pan seems dry, add a drizzle of olive oil. Add the minced garlic and cook 30 seconds, just until fragrant. Add the chopped chard and toss to coat in the oil and sausage drippings. Cook for 1 minute until it just starts to wilt (see photo above). Season lightly with salt and pepper.
Make the pizza: Line a half sheet pan (18x13) with parchment paper. Grab a sheet of parchment, crumple it into a ball, and lightly dampen it under running water. Give it a gentle squeeze to remove excess moisture, then unfold and press it into your sheet pan. Drizzle the parchment generously with olive oil, making sure the entire surface, including corners, is coated. This prevents your pizza from sticking to the baking sheet.
Stretch the Dough: Once doubled, transfer the dough to the prepared sheet pan. Use your fingertips to gently press and stretch it into an even layer all the way to the edges. *If the dough springs back, let it rest 5 minutes and continue stretching.
Par-Bake the Crust (This extra step prevents soggy pizza). Preheat the oven to 450°F. Bake the naked crust on the center rack for 5–8 minutes, just until slightly puffed and matte. Remove from the oven.
Top + Bake: Spread the tomato sauce evenly, leaving a small border. Add mozzarella and smoked Gouda, then the crumbled sausage, roasted onions, and sautéed chard. Return the topped pizza to the center rack and bake 10–15 minutes, until cheese is melted, bubbly edges are golden, and the bottom is crisp.
Garnish + Slice: Drizzle with smoked olive oil, if using. Let the pizza rest 1-2 minutes before slicing. Use a wide spatula to loosen it from the parchment. You can slide the whole pizza off the paper or slice directly on it. Serve with parmesan and crushed red pepper flakes.