I found that many people that can't tolerate garlic and/or onion can get the flavor without the tummy ache by sautéing the garlic in oil and then removing the garlic (the parts of the garlic that cause stomach troubles come out in water, but not oil). I found this version for the oven that I think is easier.
1 head of garlic, sliced in half horizontally
1 cup extra virgin olive oil
1 tsp dried thyme
INSTRUCTIONS*Preheat oven to 300 degrees F.
SOURCEhttp://www.deliciousasitlooks.com/2013/08/oven-roasted-garlic-oil.html (I only substituted dried thyme for fresh and modified the instructions accordingly)