Preheat oven to 425°; chop cauliflower into 1-inch pieces, spread on a sheet pan, drizzle with 2 tbsp oil + season with salt/pep; roast 10 min, then flip veggies over + roast 5-10 min more until browned + tender

Meanwhile, heat 1 tbsp oil in skillet over med-high; pat chicken dry, season with salt/pep, seasoning pack + cook chicken 4-6 min per side until fully cooked, no pinkness remains + internal temp is 165°

Heat 1 tbsp oil in large skillet over med-high; sauté half the spinach + salt/pep 1-2 min until wilted; add remaining spinach + cook 1-2 min more until all spinach is wilted