To make a yellow squash and tofu stir fry recipe, first you need to prepare the ingredients. First, you'll need: Yellow Squash: Peel and cut the squash in half lengthwise. Toss with 1 tablespoon of olive oil, 1 teaspoon of salt, and 2 tablespoons of red pepper flakes. Cook over medium-high heat, stirring occasionally, until tender, 8 to 10 minutes. Add 1 cup of water and bring to boil. Reduce the heat to medium and simmer until the water is absorbed, 10 to 15 minutes more. Remove from heat and stir in 1 pound of frozen yellow yams. Season with salt and pepper to taste. Serve with sour cream.