In a medium dutch oven (preferred) or deep skillet (that has a lid), heat olive oil over medium heat. Add onion and stir, cooking 5 minutes, until translucent. Add garlic and cook for 1 minute. Add rice, and stir to coat all the grains. Cook for 3 minutes, until you can see the white in the middle of each grain.
Add stock, and cook a few minutes, until absorbed. Then add water, salt, pepper, bay leaf. Bring to a light simmer. Cover and cook for 19 minutes, stirring twice.
Remove lid carefully, pulling up and not tilting to avoid water from lid going into pot. Stir and cook for five minutes, until thick but still loose. Add cheese, lemon juice, butter, cream, fennel fronds. Stir. Remove from heat and let sit for 5 minutes. Then stir until thick and creamy, but still loose.
For relish, preheat oven to 375 degrees F. Toss fennel with olive oil and 1/2 teaspoon salt. Add to a baking sheet and roast for 20 minutes, until caramelized. Remove from oven and toss with remaining ingredients.
Taste risotto for salt, and then plate, adding 1/3 cup relish to top of each portion. Leftovers will keep for 3 days in refrigerator.