Step 2) Slice onions 1/4-inch thick and put into large mixing bowl. Toss with 2 teaspoons oil and place on rimmed baking sheet. Sprinkle with salt.
Step 3) Slice the top 1/4-inch off garlic head and place on a sheet of foil. Drizzle with 1/4 teaspoon oil. Wrap garlic head in foil.
Step 4) Roast onions for 30 minutes or until caramelized, stirring every 15 minutes. Take care not to burn. Remove from oven; cool. Roast garlic for 45 to 60 minutes or until garlic is soft.
Step 5) Beat cream cheese, yogurt, Parmesan cheese, thyme and black pepper in a medium mixing bowl; set aside.
Step 6) Finely chop caramelized onions and stir into cheese mixture.
Step 7) Squeeze garlic pulp into a small bowl; smash with a fork. Stir into onion mixture and chill a minimum 15 minutes before serving. Top with green onions, if desired.
Step 8) Serve with fresh vegetables, pita chips or baked chips.