1) Preheat the oven to 350°F.
2) In a 1 1/2 quart casserole, spray with a vegetable spray.
3) In the prepared casserole, place the plum halves at the bottom.
4) Drizzle over 1 tablespoon of the honey and sprinkle with the chopped walnuts.
5) Cover, place on the middle shelf of the preheated oven and bake for 45 minutes.
6) In a medium bowl, beat the egg whites until foamy.
7) Beat in cream of tartar and 1 teaspoon honey, until stiff peaks form.
8) Spread over the plum halves and seal the edges with meringue.
9) Return to the oven and bake for about 10 minutes until the meringue is golden brown.
10) Serve the warm Plum Good Meringue on dessert plates.