Preheat the oven to 425 degrees F (220 degrees C).
This is no potato. It’s got half the carbohydrates by gram, if you’re counting, and its tart shavings can be munched raw with a dash of lemon juice or vinegar. First we'll peel it.
Use a knife to carefully peel the Celery Root (1). Once peeled, it has a creamy white complexion.
Slice the celery roots into disks, and cut the larger disks in half. Cut the Garlic (3 clove) in half the long way and chop the Red Onion (1) into large chunks.
Place everything in a bowl with Sunflower Seeds (1/4 cup), Dried Rosemary (1 teaspoon), Dried Thyme (1 teaspoon), and Salt (to taste) and Ground Black Pepper (to taste). Then add the Olive Oil (1/4 cup) and toss everything so it is evenly coated.
Roasted in the oven at 425 degrees F (220 degrees C) for 18 minutes. But consider how much crunch you like, and poke it with a butter knife after 15. Be sure to cover it most of the way (aluminum foil will do) so you don’t scorch the seeds.
Serve fresh from the oven or the next day from the fridge, perhaps sprinkled with Parmesan Cheese (to taste).