Preheat oven to 375 degrees F (190 degrees C). Line a rimmed baking pan with parchment paper. Toss the beets with a tablespoon of olive oil, and spread it onto the baking pan. Bake for 20-25 minutes, or until the beets are easily pierced with a fork.
In a small bowl, stir the red onions, raisins, dates, vinegar, and a pinch of salt together. Let it stand for 20 minutes. If there's any leftover vinegar after it's been marinated, drain it away.
Tear apart the pita into 1- to 1 and 1/2-inch pieces.
In a large pan, heat the buttery spread and 1 tablespoon of olive oil over medium-low heat. When the butter has been melted, add the pita and nuts, and stir well. Keep stirring it for about 4 to 6 minutes, or until the pita turns golden brown. Remove the pan from heat, and sprinkle on the sumac and shichimi togarashi, and mix well. Use 1 tsp of the shichimi togarashi if you want more heat in your salad.
In a large bowl, toss the spinach with the onion marinade, beets, pita, nuts, 1 tablespoon of olive oil, and lemon juice. I didn't need to add any more salt, but adjust it to your taste.
Serve immediately.