1Mix the 5-spice powder, garlic, and 2 tsp. of the soy sauce in a bowl, add the tofu cubes, and stir gently to coat. Put aside.
2In a medium sized heavy bottomed pot or wok heat 3 tsp. of the oil to medium low. Add the ginger and stirfry 1 minute.
3Add the sliced onions and sautee approx. 4 minutes until translucent but not brown.
4Stir in the ground chilis or paprika.
5Move everything in the pot or wok to one side, add the remaining tsp. of oil, dump in the marinated tofu cubes, and gently stirfry them for about a minute.
6Reduce the heat to low, stir in the halved tomatoes, sprinkle in the sesame oil or ground chipotle powder, add the remaining soy sauce, and slowly (carefully) pour in the boiling water. Let simmer, covered, for 6 minutes.
7Turn off heat, stir in the lemon juice. Taste to adjust seasoning (soy sauce, lemon, water).
8Ladle into soup bowls and garnish w/ sliced scallion. May serve w/ a bowl of rice or rice cakes on the side.