Preheat oven to 425°F and line a sheet pan with parchment paper or a silicon baking mat.
Combine cauliflower florets, garlic, red pepper flakes, and olive oil in a bowl and toss to coat.
Spread cauliflower mixture on prepared sheet pan and season lightly with salt and pepper.
Place in preheated oven and roast until cauliflower is well browned, about 30 minutes.
Heat lemon juice and cream cheese in microwave for about 45 seconds until warm; mix until smooth.
Toss warm roasted cauliflower with lemon-cream cheese mixture and garnish with chopped green onions. Serve warm or chill until ready to serve.
Line your baking sheet with parchment, or (even better) a silicone baking mat. Lining your pan is essential to prevent sticking and make clean-up a lot easier. Plus, using a silicone baking mat like this one helps everything cook more evenly.Season lightly at first, then add a little more salt and pepper as your last step. This dish is easy to season after it's cooked, so to avoid oversalting, just salt it lightly before roasting and then once you've tasted your finished product, add more salt and pepper if needed.Serve warm OR cold! I like to enjoy this creamy roasted cauliflower warm as a side dish, but I've also had it chilled as a picnic side dish -- it can be a delicious, low-carb alternative to pasta salad or potato salad!