Creamy Chicken Gravy

Melt butter in a saucepan over medium-high heat; add red onion. Saute until translucent, about 3 minutes. Add garlic; cook and stir until fragrant, about 1 minute. Season with thyme, salt, and pepper.

Pour wine into the saucepan; simmer until wine has reduced, about 3 minutes. Pour in chicken broth, milk, and bouillon; stir. Reduce heat to low, cover the saucepan, and simmer gravy until flavors meld, about 1 hour.

Combine water and flour in a bowl; mix thoroughly. Pour slowly into the gravy while stirring continuously. Simmer until thickened, 15 to 30 minutes more.