Heat rhubarb, strawberries and orange juice in medium saucepan to boiling. Reduce heat, cook 10 minutes or until fruit is tender.
Remove from heat. Add sugar to taste. Cool slightly.
Place 1/2 fruit mixture in blender or food processor. Cover; blend until smooth. Repeat with remaining fruit.
Refrigerate covered. Garnish with additional strawberry slices, if desired. Serve with Almond Macaroons.
Almond Macaroons: Combine almond paste and 3 tbsp. plus 1 tsp. sugar in food processor. Cover; pulse to blend well. Gradually add egg white and blend until smooth and dough has formed. Place batter in medium size pastry bag fitted with small round tip. Pipe batter into small circles on parchment-lined baking sheet. Bake at 325°F. for 10 to 12 minutes or until just begins to brown on edges. Cool briefly and loosen with spatula.