Make Decadent & Delicious French Onion Soup

Step 2 First you caramelize the onions.

Melt butter and oil in a heavy 4 quart deep, wide pan. Add onions and toss to coat. Cook over low-medium heat, flipping onions occasionally, about every 10-15 minutes. When onions are tender and translucent, raise heat to medium high and stir in salt.
Cook for about 30 minutes, flipping/stirring often until onions turn golden brown.