-
Warmth the butter in a mammoth pot over medium-high heat. Add the onions, 1¼ teaspoons salt, and ¼ teaspoon pepper and cook dinner, covered, stirring every so step by step, till soft, 12 to fifteen minutes. Decrease heat to medium and cook dinner, uncovered, stirring every so step by step, till the onions are golden brown, 50 to 60 minutes.
-
Add the wine and cook dinner till a bit reduced, about 2 minutes. Add the broth and 6 cups water and elevate to a boil. Decrease heat and simmer for quarter-hour.
-
Within the interim, heat broiler. Scheme the bread on a broilerproof baking sheet and broil till golden brown and crisp, 1 to 2 minutes per aspect. Sprinkle with the cheese and broil till melted, 1 to 2 minutes.
-
Divide the soup among bowls, high with the toasts, and sprinkle with the thyme.