In the bowl of your food processor, fitted with the blade attachment, add the cauliflower florets and process until it resembles rice. Place the cauliflower crumbles into a large bowl.
Add the fresh parsley and mint leaves to the bowl, secure the lid and pulse until finely chopped. Add the herbs to the bowl with the cauliflower, along with the chopped tomatoes, green onions and cucumber.
Grate in the garlic and pour in the lemon juice and olive oil. Season with kosher salt and fresh ground black pepper to taste.
Serve immediately or refrigerate until ready to serve.