In a large soup pot or Dutch oven over medium heat, cook the smoked sausage and ground beef for about 4 minutes, until the meat begins to brown. Break up the ground beef as it cooks.

Add the diced onion and sauté for another 4 minutes, stirring occasionally, until it begins to soften.

Add the minced garlic and Cajun seasoning. Sauté for 1 minute, stirring frequently.

Stir in the drained fire-roasted tomatoes, kidney beans, and navy beans.

Pour in 8 cups of chicken broth and add the sliced collard greens. Stir to combine.

Use the back of a spoon to gently smash a few beans against the side of the pot. This will help thicken the broth as the soup simmers.

Bring the soup to a gentle simmer and cook uncovered for at least 20 minutes, or up to 40 minutes, until the collards are tender and the broth has thickened slightly.

Add more chicken broth as needed to reach your preferred consistency.

Taste and adjust the Cajun seasoning as needed. Serve hot.