- Pre-heat grill to medium heat 350-375F (175-190C).
- In a small saucepan, melt butter on low heat for approximately 15 minutes. Add garlic cloves in the last five minutes. When the butter foams and milk solids sink to the bottom, remove from heat.
- Using spoon, remove foam. Using a sieve or cheese cloth, strain butter into bowl, removing the milk solids and garlic. Add one teaspoon (five milliliters) of caraway, ground black pepper and salt. Set aside.
- Wash heads of cauliflower.
- Cut off leaves and most of the stem, leaving 1.25 centimeters of the stem to keep the head intact.
- In a large pot, bring vegetable stock and turmeric to a boil. Add one teaspoon (five milliliters) of caraway and peppercorns. Submerge cauliflower head, one at a time for two to three minutes. Remove and drain.
- Set heads aside until cool enough to touch.
- Place one holding fork on the spit rod tines. Slowly and carefully insert the stem end of one cauliflower head. Repeat with second cauliflower head. Place another holding fork on rod and insert through both heads of cauliflower, carefully and slowly.
- Adjust the forks and tighten screws, testing the balance. Fine-tune as necessary.
- Attach spit over grill. Turn on motor. Close lid.
- Cook cauliflower for 15-20 minutes, basting with garlic-caraway butter every five minutes. Remove cauliflower from grill when tender and golden brown.
- Carefully remove heads of cauliflower from rod tines.
- Cut in half or quarters. Serve immediately on a bed of arugula drizzled with walnut oil and lemon juice.
Note: Cooking times and temperatures will vary depending on the size and type of your barbecue.