Put the bacon in a saucepan and cook, stirring often, until crisp. Add the carrots, celery, and cook, stirring, about one minute.
Add the peas, garlic, about 1 1/4 quarts of water, or to barely cover, thyme, bay leaf, salt, and red pepper flakes. Bring to the boil and let simmer, uncovered, 30-40 minutes, until tender but not mushy. Remove from heat.
Put the rice in a saucepan and add 1 1/2 cups water and salt to taste. Bring to the boil and let set 17 minutes. Stir in the butter.
Cut the unpeeled tomato into 1/4 inch cubes; there should be about one cup.
Arrange the hot rice in the center of a platter. Spoon the hot pea mixture, including liquid, over the rice. Scatter the cheese over the peas. Place tomato cubes around the rice. Scatter the scallions over the tomatoes. Serve immediately.