Step 1Combine the oil, shallots, garlic and 1 teaspoon salt in a large saucepan. Set over medium heat and cook, stirring often (you don’t want them to stick or burn), until the shallots are translucent and tender, about 10 minutes.
Step 2Add the creminis, thyme and a generous pinch of salt and pepper. Raise the heat to medium-high and cook, stirring often, until the mushrooms release their juices and then reabsorb them, about 25 minutes. They’ll start sizzling in the oil again.
Step 3Add the mushroom powder and stir for 1 minute. Add the bourbon and stir well, scraping up any bits from the pan, until the alcohol burns off, 2 to 3 minutes. Add the broth and bring to a simmer, stirring often. Discard the 4 thyme stems and season to taste with salt and pepper. For a thinner gravy, add more broth. Keep warm over low heat until ready to serve.
Red Wine Mushroom Gravy: Substitute a dry red wine for the bourbon.
Button Mushroom Gravy: Substitute white button mushrooms for the creminis.