Slice the pressed tofu into 1-inch thick cubes. Whisk the lemon juice and the first portion of soy sauce in a large bowl, then toss the tofu in the mixture and let it marinate for at least 10 minutes.

Heat a large nonstick skillet with a lid over medium-high heat. Add the oil and, once shimmering, fry the tofu pieces until browned and crisp on all sides, about 10 minutes total. Remove the tofu and set aside on a plate.

Add the onion and garlic to the same pan and sauté for 1 minute until fragrant. Add the bell peppers and sauté for 2 more minutes until the edges begin to soften.

Pour in 2 cups of the vegetable broth, the remaining soy sauce, tomato paste, sugar, and the carrot. Cover the pan and bring the liquid to a boil over high heat.

Simmer the carrot for 5 minutes, then add the potato. Cook for another 5 minutes until both vegetables are halfway tender.

Return the fried tofu to the pan and lower the heat to medium-high. Simmer for 5 to 10 minutes, stirring every couple of minutes to prevent the sauce from sticking, until the vegetables are tender and the sauce has thickened.

Stir in the green peas and adjust the consistency with the remaining broth if the sauce is too thick. Season with salt and pepper to taste and serve hot over steamed rice.