Cauliflower mash is the low carb swap that actually holds up. Pair with grilled chicken and you won't miss the potatoes — the butter and cream do the work.
Pat chicken breasts dry with paper towels; brush both sides with olive oil and season evenly with half the salt, black pepper, and garlic powder.
Preheat a grill or grill pan to medium-high heat (about 400°F). Place chicken on the grill and cook for 5–7 minutes per side, until nicely charred and an internal temperature of 165°F is reached. Rest for 5 minutes off the heat.
While the chicken grills, add cauliflower florets to a large pot of boiling salted water and cook until very tender but not waterlogged, about 10–12 minutes.
Drain cauliflower well and let stand in the colander for 2 minutes for excess moisture to evaporate. Mash or process cauliflower with butter, heavy cream, and remaining salt until creamy; fold in parmesan cheese and adjust seasoning to taste.
Serve chicken breasts sliced over a generous mound of cauliflower mash. Sprinkle with additional black pepper or fresh herbs if desired.