Preheat oven to 375 degrees.
Line a baking sheet with parchment paper.
Heat a skillet over medium-low heat and add the olive oil and butter.
Add the onion and cook until softened and translucent, about 5 min.
Add the garlic and cook for 30 sec.
Remove the skillet from the heat.
Place the beef in a large bowl along with the crumbled toast, salt & pepper, worchestershire sauce, tomato and BBQ sauces, egg and onion. (I dump the all contents fro the onion skillet into the bowl, including the leftover butter/oil).
Use your hands to gently combine the mixture and bring it together, evenly distributing the ingredients but trying not to over-mix. Form the mixture into sliders- depending on how large you form these, you will get 8-12 sliders.
I make mine about 2" in diameter and slightly less than 1" in thickness.
Place the sliders on the baking sheet.
Bake for 15 min.- then remove from the oven and spoon 1-2 TBS of the topping sauce over them.
Bake for another 10-15 min.- then remove them from the oven and can serve on Hawaiian slider rolls, regular white slider rolls, or over cornbread.