Well, probably my signature dish would be " barbecued potatoes"
Basically made it up as I was a student, didnt have much money, and kinda grabbed whatever I could in the house, mixed it all together and baked/ broiled it. Its a hit everywhere i go. There are no measurements basically it is honey, mustard, ketchup, soy sauce,cheap barbecue sauce, garlic, oil, onion and garlic powder, potatoes. Basically, i gut the potatoes into bite sized pieces ( skins on) , then put them in plastic bag and microwave until cooked ( a few minutes). I then mix all the wet ingredients and stir the potatoes in until the potatoes are completely coated. I then take a glass or ceramic dish to bake them in, but I put some foil in the tray to cover the bottom. I place the coated potatoes (single layer, all must be touching the bottom surface to obtain a nice crispy, slightly burned/ caramelized surface). I baste the top surface again, then bake about 1/2 hour at 425F, take them out, baste again, sprinkle with onion and garlic powder, turn the oven down to about 375 and another 15 - 30 minutes, take out and baste again, more onion and garlic powder , then back in the oven, turn it off, but let them sit there another 1/2 hour or so. finally, take them out again, more garlic and onion power, and let them cool until slightly warm/ room temp. Its a pain in the "you know where" to make, but they are soooo good, and go %100 every time. In my opinion, the honey is the key ingredient, something about the sweet/ mixed with the rest works so well. Oh yeah, sometimes i add a little vinegar in too, but not much.
Anyway, the other dish , that people probably see as " me" would be the Linguini with fresh tomatoes, basil, garlic and oil ( served at room temp). Its simple, fresh, easy,but the only problem is that it is one of those thins u need to make and serve immediately. The longer it sits, the pasta has a weird reaction with the tomatoes/ oil and gets kinda slimy, so i hate making it in advance so that is why i dont bring it that often.
But, I think one of the worst things is when someone makes your " signature dish". They do it half-a$$ed, or all wrong, serve it, then tell everyone how it is your signature dish, even though they ruined, i mean , made it .