I am planning to use this with chicken to make a cacciatore-like dish.
Fresh Tomato & Fennel Sauce
1 medium bulb of fresh fennel
1/2 to 1 teaspoon fennel seeds, slightly crushed
8 to 10 fresh Roma tomatoes
1/4 teaspoon Herbs de Provence
1/8 teaspoon red chile flakes
4 to 6 small mushrooms, or stems from about 18 mushrooms
salt and pepper to taste

You'll end up with about 4 cups of tomatoes.
In a large, good quality non-stick saute pan, cook the fennel over medium-high heat. Allow to brown slightly, and cook until a bit softened. Add the tomatoes, herbs, and chile flakes. Cover and cook over medium-low heat until the tomatoes begin to cook down a bit. Give a good stir.

Add the tomatoes, herbs, chile flakes, and cover. Cook on medium-low.
The Roma tomatoes produced more liquid that I anticipated, so I was looking for something to thicken the sauce a bit without having to cook it down too much. I had cleaned some some mushrooms for another use, and thought I’d try pureeing the stems. That way my roasted mushrooms could be just caps (more attractive) and I wouldn’t waste the stems.

Hmm ... that's a lot of liquid.
Clean and trim the mushrooms (or stems). Place in a blender or food processor and pulse to chop them a bit. Ladle about 1/2 to one cup of the the cooked sauce into the bowl of the blender and process mixture until smooth. Add to the sauce, stir, and cook a few more minutes.

The finished sauce. Perhaps not the prettiest, but it will be wonderful with grilled chicken.
This makes a total of about 2 cups of sauce.
For my Challenge, I will count this as a vegetable.