In a large dutch oven or soup pot add 4 tablespoons of butter and set over medium-high heat.

When the butter is melted add the sliced onions and garlic, and cook until the onions start to soften and pick up a tiny bit of color, about 15 minutes. Make sure your onions are not burning, if so turn down the heat slightly.

Add the kosher salt, black pepper, and granulated sugar. Stir to combine.

Continue cooking, stirring occasionally, until onions are deep golden brown and caramelized, about 35-45 minutes. Again, reducing heat slightly if onions seem to be browning too quickly.

Stir in the tomato paste.

Add wine and raise heat to high.

Cook until almost all liquid has evaporated, about 8 to 10 minutes.

Add broth and herbs to pot with onions. Optional: tie the herbs into a bundle with kitchen twine so they are easy to remove.

Bring to a boil, reduce to a simmer, and cook, uncovered, until broth is thickened and flavorful, about 20 to 30 minutes.

Remove from heat and whisk in the remaining 2 tablespoons of butter.

Taste the soup and adjust seasoning if needed.

Turn on your broiler or if you do not have a broiler set your oven to 450 degrees.

Layout 6 oven-safe soup bowls or ramekins onto a rimmed baking sheet.

Add 1/2 teaspoons sherry to the bottom of each bowl.

Spoon soup into the bowls, top with baguette slice, and top each bowl with an equal amount of shredded cheese.

Place your soup under the broiler or in the oven to help melt the cheese.

Serve bubbling hot.