Red beans and rice is a great dish for people looking to gain weight. It's protein packed and really simple to make. Just sauté diced onions with a bay leaf, add cooked rice and canned beans, dump your favorite spice mix, and stir well. When using left-over rice, which is what I did today, the time from stove to table is 10 minutes max.
"Give me a sista, can't resist her, red beans and rice didn't miss her..." Ah, even Sir Mix-a-lot gives props to the vegan diet.