- Preheat the oven to 425 degrees F. 
- Pound your thyme, chili and a little of the garlic in a pestle and mortar or shaker. 
- Squeeze in the lemon juice and add the olive oil. 
- With your hand or a brush, rub the mushrooms all over with this mixture. Make sure all the flavored oil is used up. 
- Tightly pack the mushrooms together, bottom side up, in an ovenproof dish or roasting pan, and with a knife make 2-3 slits randomly over each mushroom. Insert a slice of the remaining garlic into each slit. 
- Dot some olive oil over the mushrooms, season and bake for around 15-25 minutes - cooking time depends on the size of the mushrooms. Cook until they are soft, slightly colored and juicy. 
- Taste one to see, continue cooking if need be. You can also use these as a topping to your favorite salad.