Adjust rack to top position (top and middle positions for 4 servings) and preheat oven to 425 degrees. Wash and dry produce.

Halve, peel, and cut onion into ½-inch-thick wedges; mince a few wedges until you have 2 TBSP (4 TBSP for 4). Peel and mince or grate garlic. Roughly chop pistachios. Drain and rinse chickpeas; pat very dry with paper towels. Roughly chop cilantro. Zest and quarter lemon.

Melt 1 TBSP butter in a small pot over medium-high heat (use 2 TBSP butter and a medium pot for 4 servings). Add minced onion, half the garlic, half the pistachios (save the rest for serving), half the Shawarma Spice Blend (you’ll use the rest in the next step), and a pinch of salt. Cook, stirring, 1 minute.

Stir in rice, ¾ cup water (1½ cups for 4), stock concentrate, and a big pinch of salt. Bring to a boil, then cover and reduce to a low simmer. Cook until rice is tender, 15-18 minutes.

Keep covered off heat until ready to use in Step 5.

Meanwhile, toss onion wedges, tomatoes, and chickpeas on a baking sheet with a large drizzle of olive oil, remaining Shawarma Spice Blend, a few pinches of salt, and pepper. (For 4 servings, divide everything between 2 baking sheets; roast on top and middle racks, tossing veggies and swapping rack positions halfway through roasting.)

Roast on top rack, tossing halfway through, until veggies are tender and lightly charred and chickpeas are crispy, 18-20 minutes. (It’s natural for chickpeas to pop a bit.)

While veggies and chickpeas roast, in a small bowl, combine sour cream with remaining garlic to taste. Season with salt. Stir in water 1 tsp at a time until mixture reaches a drizzling consistency.

Rinse shrimp* under cold water, then pat dry with paper towels. Season all over with salt and pepper. Heat a drizzle of oil in a large pan over medium-high heat. Once pan is hot, add shrimp and cook, stirring occasionally, until opaque and cooked through, 4-6 minutes. Transfer to a plate.

Fluff rice with a fork; stir in half the cilantro. Season with salt and pepper.

Toss veggies and chickpeas with lemon zest.

Divide rice between shallow bowls or plates. Top with veggies and chickpeas. Drizzle with garlicky white sauce and hot sauce to taste. Sprinkle with remaining pistachios and cilantro. Top with lemon juice to taste; serve with any remaining lemon wedges on the side.

Serve shrimp atop bowls.