I make these and double the recipe.
I wrap each burger and lay on a cookie sheet till frozen then bag, they keep in the freezer about 3 months. It's a great recipe for when ground chicken or turkey is on sale.
To rehydrate the tomatoes, place in a bowl and cover with warm water.
Leave the tomatoes in the water until they have plumped up, about 20 minutes.
Strain the tomatoes and save the water to add to the risotto with the chicken stock for added flavor.