Set grill or oven to 350F.
Mix ground bison with the seasonings and form into 8 small patties.
Thoroughly wash the mushrooms. Chop the stem off the mushroom caps. Using a small knife or spoon, carefully scrape out the inner black portion of the mushroom caps. Spray the caps with a little olive oil, then toss them face down on the grill or in the oven for no more than 8 minutes. This will help soften them a bit.
Add the bison patties to the grill and cook for about 10 minutes. Then, flip them over to cook for another 5 minutes or so (to desired readiness).
Cut each cheese slice into 4 equal squares, then place the square of cheese on each slider and let the cheese melt on the slider for 1 – 2 minutes.
Assemble the slider. Squeeze a bit of Dijon into one of the caps, then add maché (lettuce), 1 tomato slice, the bison patty and then top with the other mushroom cap. Skewer with a toothpick or wooden stick if needed.