For Horseradish Aioli:

1. To a medium bowl add mayo, prepared horseradish, whole grain mustard, lemon juice and garlic powder. Stir to mix everything together and set aside.

For Brisket:

1. To a small bowl add garlic powder, smoked paprika, salt, black pepper, onion powder, ancho chili powder and thyme. Mix everything together.
2. Rub spice blend into both sides of the brisket.
3. Place seasoned brisket in a large (2-3 gallon) ziplock bag. (or you could place on a baking sheet on cover with tin foil) Let the brisket sit overnight.
4. Add seasoned brisket to a slow cooker. (you may need to cut it up to make it fit)
5. Next add sliced onion on top and cover with your choice of beer.
6. Cover and cook on HIGH for 6 hours.
7. Turn the broiler on to HIGH.
8. Line a baking sheet with tin foil. Remove brisket from the slow cooker and place on prepared baking sheet.
9. Place brisket in the oven and broil on HIGH for 5 minutes. (this will give you a nice “char” and burnt ends type taste)
10. Slice brisket. (you could add the sliced brisket back into the beer to keep it moist if you aren’t serving it right away)

Assemble Sliders:

1. To each Hawaiian roll add 1 teaspoon of horseradish aioli, a small handful of arugula and 2 slices of brisket.
2. Repeat process until all the sliders are prepared.
3. Serve.