I'm sure you can find a load of how-to's on the internet for carmelizing onions, but I'll just give you my easy way.
3 Tbsp butter
1 maui onion, sliced
In a heavy bottomed skillet, saute onions and butter on Med-Lo heat. Stirring occasionally.
The trick is that you don't want to stir too little -- or it'll burn. But you don't want to stir too much -- or it'll never brown. If you don't have maui onions, you can add a little bit of sugar to help get the browning on. Salt and a little bit of water will help preventing the burning. However, if you want savory, well-developed, carmelized onions, you need to have patience. I'm sure you can get a batch out in less than 10 minutes, but they probably won't look like those brown rice noodle type onions that melt in your mouth.
Now that you have the recipes for everything. Grab some thick slices of your favorite bread. Let's put it all together!
The trick to getting delicious panini is MAYONNAISE. Yup, mayo. But not on the inside (necessarily), in order to get those lovely brown sears on the outside, you need it. I know a lot of people are against mayo. I actually know two people that will scrape Boursin out of a sandwich because it resembles mayo, and one can't be too sure it's not. (Here's where I shake my head. Mayo is delicious.) But if you're one of those people, you could use butter or some other grease.
I know you want to jump right in and start building up your panini. Don't. I know you want to see it come together and fantasize about the orgy on your tastebuds. But please, be patient. Make sure your panini press, grill, pan (what have you), is nice and hot. If it's not, you'll just end up with a greasy mess.
Slather about a tablespoon of mayo on one side of your bread, place it, mayo side down on heat source.
Arrange your pulled pork onto that slice, you can make it as loaded as you want, but remember if it's too full, it'll take longer to be ready. You can add a dollop of bbq sauce over the meat at this time, or serve it as a dipping sauce along with the panini. Mmmmmm bbq sauce.
Add some carmelized onions.
From the cold mac and cheese, place a square directly onto your panini. We found that we had to slice it in half, height-wise. It was just too much for the ratio.
Add more cheese if you dare!
Slather another tablespoon of mayo on another slice of bread. Place mayo side out, on your panini.
There you have it. If you have a panini press, close the lid and wait for the green light. If you're using less techno-gizmo savvy methods, flip and smash down to get a hot, cheesy, melty sammy. Honestly, this thing was so filling, I only finished half.
Mmmm.. but it made some mean leftovers to bring to work. wink