For the dressing: Combine the olive oil, parmesan, salt, pepper, sugar, paprika, lemon juice and garlic in a jar. Shake it up and store it in the fridge until using. For the salad: Combine the greens, red onion and radishes in a large bowl. Discard the garlic from the dressing and shake well again, then drizzle about half over the salad. Season with salt and pepper. Toss well, adding more dressing if needed.