Wash and dry all produce. Preheat oven to 425 degrees. Toss cauliflower on a baking sheet with a drizzle of olive oil. Season with salt, pepper, and 1/2 tsp Turkish spice. Roast until tender and lightly browned, about 25 minutes.

Thinly slice scallions, keeping greens and whites separate. Halve, peel, and finely chop the onion.

Bring water and a large pinch of salt to a boil in a large pot. Once water is boiling, add gemelli pasta. Cook until al dente, 9-11 minutes. Drain.

Heat butter in a large ovenproof pan over medium-high heat. Add onion and scallion whites. Cook until softened, 3-5 minutes. Add 1/2 tsp Turkish spice (we sent more) and cook until fragrant, about 1 minute.

Whisk flour into pan and cook until golden, 1-2 minutes. Slowly pour milk into pan while whisking to combine. Stir in stock concentrate and bring to a simmer. Let bubble until thickened, about 2 minutes. Remove from heat and add cheese, stirring until cheese is melted. Season with salt and pepper.

Add cooked pasta and cauliflower to cheese sauce and stir to combine. (TIP: Transfer mixture to baking dish if you don't have an ovenproof pan.) Bake until top is lightly crisped, about 5 minutes. In a large bowl, toss mixed greens with balsamic vinegar and a drizzle of olive oil. Serve on the side.