Directions Step-By-Step. In a microwave safe baking dish, thinly slice unpeeled potatoes and onions.(you can peel also, i love the flavor with peel). 1. Liberally spray potatoes and onions with pam cooking spray.(You can also use veg. oil).2.n a microwave safe baking dish, thinly slice unpeeled potatoes and onions.(you can peel also, i love the flavor with peel). 1.