Simmer the tempeh (10 minutes). Put the cubes in a pot with 2 cups (480 ml) of water and simmer. This is a common step to mellow tempeh’s bitter edge. Drain, then set aside about one quarter of the cubes for the garnish.
Soften the vegetables (6 to 8 minutes). Warm 2 tbsp (30 ml) of olive oil in a large pot over medium heat. Cook the onion, carrot, and celery until they are soft and the onion is translucent. Don’t let them brown, since you want a pale, clean-tasting soup.
Build the base (about 1 minute). Stir in the garlic for 30 seconds, then the tomato paste and smoked paprika. Cook until the paste darkens to a brick red and smells sweet and toasty.
Simmer (25 minutes). Add the larger portion of tempeh, the rice, stock, and soy sauce. Bring to a boil, lower the heat, and simmer with the lid slightly ajar. The soup is ready when a grain of rice crushes to mush against the side of the pot.
Crisp the garnish (4 to 5 minutes). While the soup simmers, heat 1 tbsp (15 ml) of olive oil in a small skillet over medium heat. Fry the reserved tempeh, stirring now and then, until the cubes are golden and sizzling loudly, then pull them onto a paper towel.
Blend (1 to 2 minutes per batch). Let the soup cool for 5 minutes. Blend in batches, filling the blender no more than half full and leaving the lid vent open under a folded towel so steam can escape. The soup should be pale gold and feel completely smooth. For a restaurant-fine texture, press it through a sieve.
Add the cream (3 to 4 minutes). Pour the soup back into the pot over low heat. Stir in the cream and warm gently until steaming. Do not let it boil.
Finish with yuzu. Take the pot off the heat. Stir in 1 tbsp (15 ml) of yuzu juice, taste, and add more a little at a time until the soup smells bright and the richness lifts. Season with salt and pepper.
Serve. Ladle into warm bowls and top with the crisp tempeh and chives.