Cook baked macaroni without an oven?

Yes, you could do it without a oven. It can be prepared in the microwave or on the stove. The trick may be the browning of the top. If a full sized oven or a toaster oven can't be used for a couple of minutes of broiling to "finish" the dish, some folks have been known to take a propane torch and (very carefully!) brown the top that way. Many commercial eating establishments use the torch to make crème brûlée (which is French for "burnt cream") since the only "trick" to this wonderful dessert is the browning of the top. The torch is a tool of the trade for chocolate and candy sculptors, and is finding more applications in the kitchen. In a pinch, take enough bread crumbs to pretty much cover the top of the dish, and toast them in a skillet. Sprinkle over the finished product to give it a "baked" look. Bon appétit!