Press the tofu if you haven't already - see note. Cut it into cubes.
Pour the marinade into a plastic Ziploc bag: 2 tbsp soy sauce, 2 tbsp pineapple juice and ½ inch of fresh peeled ginger. Add the cubed tofu and mix around so it's all covered with marinade. Place in the fridge for at least 30 minutes.
Preheat the oven to 400 degrees F. Line a baking sheet with parchment paper and set aside.
When the tofu is done marinating, remove the tofu and place in a single layer on the prepared baking sheet. Bake for 25-30 minutes, flipping each piece half way through the cooking time.
In the meantime, whisk together the stir fry sauce: tomato paste, 3 tbsp soy sauce, 2 tbsp pineapple juice, maple syrup, and vinegar. Mix together the cornstarch and water and add to the sauce. Whisk well and set aside.
Heat a large skillet with 2 tbsp water (or broth) over medium-high heat. Add the garlic and ginger and sauté for 3 minutes.
Add the carrots and ¼ cup water (or broth), cover and let cook about 5-7 minutes. Check every few minutes and add more water/broth if the pan is getting dry. Add the snow peas, water chestnuts, scallions and pineapple chunks and cook another 2-3 minutes.
Add the stir fry sauce and mix well. Add the baked tofu and mix again.
Serve over rice and garnish with sliced green onions, sesame seeds and a sprinkle of sesame oil, if desired.
*To press tofu - place paper towels or a clean dishcloth on a plate and place block of drained tofu on top. Cover with more paper towels or another clean dishcloth, add another plate on top, and weigh it down with whatever you have. I used bags of dried beans or grains.~To save time, chop your veggies while the tofu is marinating. You can make the stir fry sauce at this time too.~The stir fry comes together quickly if you have everything prepped ahead of time. Don't start your stir fry until you have about 15 minutes left for baking the tofu. That way everything will be ready at the same time.~Nutrition facts calculated without garnishes or rice.