Drain the clams and reserve the liquid.
Cook the bacon at full power in the microwave for 1 minute. Add the onion and cook for 1 minute. Add the flour, thyme, and bay leaf, and cook for 30 seconds. Incorporate the clam liquid and stir well. Slowly add the broth and hot water, mixing well. Add the potatoes, salt, and pepper. Bring to a boil at full power in the microwave for 5 minutes, then reduce the power to medium for another 5 minutes or until the potatoes are tender. Add the tomatoes, clams, and lemon juice. Cook for 4 to 5 minutes at medium power (if necessary). Garnish with chopped parsley. Serve.