I picked up a pair for $2.69 (there's also a plain version with just roast beef on the slider buns for the same price).
Mighty Minis were offered earlier this year in select participating markets and it looks like they did well enough to be offered nationally.
The buns are dusted with flour and are probably the same size as a typical French roll at the supermarket if you count them together. They have a soft dinner-roll feel to them and are fairly dense. I thought they paired rather well with the other ingredients and cut against the saltiness of the roast beef.
The star of the show were the crispy onion strings, which were similar to French's but fresh. There's a pronounced, seasoned, caramelized onion flavor to them that you don't quite get with onion rings. Along with the au jus sauce, they really set off the roast beef.
The au jus sauce was subtle but adds an extra savory beefiness that gave the roast beef some extra 'oomph.'
The roast beef was sliced razor thin and tender but lacking texture, which is pretty par for the course for Arby's. It didn't feel as salty as usual, which led me to enjoy it more than usual.
Overall, I'm pretty glad I tried Arby's new Onion Mighty Minis. The flavorful, crispy onions and extra beefiness of the au jus really made eating them enjoyable.
Nutritional Info - Arby's Onion Mighty Minis (184g)
Calories - 550 (from Fat - 270)
Fat - 30g (Saturated Fat - 7g)
Sodium - 1260mg
Carbs - 47g (Sugar - 6g)
Protein - 23g