Brown the Meat: In a large pot or Dutch oven, brown the deer meat over medium heat. If using diced meat, cook until tender. Drain excess fat if necessary.
Add Seasonings: Stir in all the seasoning. Add the salt, and pepper to taste. Cook for an additional 1-2 minutes to toast the spices.
Add Mushrooms, Rotel Tomatoes and Beans: Pour in drained mushrooms, diced tomatoes (with juice) and add the chili and black beans. Stir to combine.
Simmer: Bring the mixture to a boil, then reduce heat to low. Cover and let it simmer for 30-45 minutes, stirring occasionally. If you like a thicker chili, simmer longer without a lid.
Taste and Adjust: Before serving, taste and adjust the seasonings if necessary.
Serve: Ladle the chili into bowls and add your favorite toppings.