In a large mixing bowl, combine ground venison, ½ cup finely diced onion, panko breadcrumbs, ketchup, egg, minced garlic, salt, worcestershire sauce, and dijon mustard.

Use clean hands to combine the ingredients until everything is fully incorporated.

Form into 4 equal sized oval patties, about ½ inch thick.

Place on a plate and refrigerate for at least 30 minutes.

When ready to cook, heat oil in a large deep skillet over medium heat.

Depending on the size of your skillet, you may have to work in stages to not overcrowd your pan. Place 2-4 patties carefully into the skillet and cook for 4-5 minutes until a nice golden crust has formed. Flip and finish cooking, about 5 more minutes. Remove finished patties to a plate to the side.

To the same skillet, melt butter. Add remaining diced onions and minced garlic and cook until translucent, around 2 minutes.

Add sliced mushrooms and cook for about 5 minutes.

Add flour and stir to coat the mushrooms.

Slowly add in broth, stirring as you do so. Once the broth is fully added, allow to thicken on low heat for 5 minutes.

Add chopped thyme leaves, stir, and remove from heat.

Serve patties with sauce and enjoy.