Ingredients

• 2 tbsp olive oil or butter
• 3 large yellow onions (~2 lbs), thinly sliced
• 1 tsp sea salt (helps draw out moisture for faster caramelizing)
• 2 garlic cloves, minced
• ½ cup dry white wine (or sub low-sodium veg broth for alcohol-free)
• 6 cups low-sodium beef or mushroom broth (certified low-sodium for heart health)
• 1 tsp fresh thyme leaves (or ½ tsp dried)
• 1 bay leaf
• Freshly ground black pepper
• Topping per bowl:
– 1 slice whole-grain or low-carb baguette-style toast
– 2 tbsp grated Gruyère or Swiss cheese (or nutritional yeast + vegan cheese for dairy-free)

Instructions

Caramelize onions: Heat oil in a heavy pot over medium-low. Add onions and salt. Cook 35–45 min, stirring every 5–7 min, until deep amber and jammy. Low and slow is key!
Add garlic; cook 1 min. Deglaze with wine, scraping up browned bits. Simmer 3–4 min until mostly evaporated.
Stir in broth, thyme, bay leaf, and pepper. Simmer uncovered 25–30 min to meld flavors. Discard bay leaf.
Broil topping: Ladle soup into oven-safe bowls. Float a toast slice on each. Sprinkle generously with cheese.
Place bowls on a baking sheet. Broil 2–4 min—until cheese is bubbly and golden. Watch closely!
Rest 3 min before serving (hot bowls + molten cheese = caution!).