• For garnish, extra chile flakes or cheese
In a 2- to 3-quart saucepan with a lid, bring the water to a rolling boil. Pour in the polenta while whisking continuously. Stir in the salt and continue whisking until the polenta has thickened slightly. Reduce heat to low and cover. Cook the polenta for 20 to 30 minutes, whisking vigorously every 10 minutes. The polenta is done when it is creamy, tastes tender and has thickened into a porridge.
Remove the polenta from heat and stir in the cheese until the cheese has melted. Cover the pot and set aside until ready to serve.
When the polenta is about 10 minutes from finishing, prepare the topping. Heat the olive oil in a skillet and add the chicken sausage. Cook, stirring occasionally, until the sausage is browned and golden on all sides, 3 to 4 minutes. Add the garlic and chile flakes, and stir until fragrant, about 30 seconds. Stir in the cherry tomatoes and cook until the tomatoes are soft, 1 to 2 minutes. Sprinkle handfuls of the spinach over the pan, adding more as each handful begins to wilt. Cook until the spinach is wilted and silky, but still bright green. Sprinkle with salt and remove the pan from heat.
Fill a saucepan with about 2 inches of water and set over medium-high heat. Crack each of the eggs into a measuring cup and set near the stove. When the water comes to a rapid simmer, reduce the heat to low and slip the eggs into the water one at a time. Cook for 4 1/2 minutes for runny yolks or 5 1/2 minutes for set yolks. Remove with a slotted spoon and transfer directly to polenta bowls.