This recipe came out of an old issue of Prevention magazine -- it's what passed for "health food" in the 70s, I guess. It calls for parmesan cheese, but I usually use cheddar. Your choice!

Tian de Courgettes au Riz
Printer version of this recipe

2 lbs. zucchini
1/4 cup olive oil (+2 Tbsp)
1 lg onion (minced)
2 T flour
2-4 lg cloves garlic (minced)
1 1/2 C liquid (milk)
1 1/2 cups cooked brown rice
1/2 tsp. thyme
salt and pepper
3/4 cup cheese (parmesan, or cheddar if you prefer) (+2 Tbsp)

Coursely grate zucchini into a sieve set over a bowl.
Squeeze & press zucchini down to extract liquid into bowl.
Simmer onion in oil for 5 minutes.
Add zucchini and garlic, toss and stir for 2-3 minutes.
Stir in flour and cook another couple of minutes.
Pour zucchini juice into measuring cup -- add milk to equal 1 1/2 cups.
Blend milk mixture into pan.
Add rice, seasonings and cheese.
Pour into greased baking dish. Sprinkle with 2 T each of oil and cheese.
Bake at 425° until hot and bubbly, a little browned.

(I think you could cut back a wee bit on the olive oil, but otherwise, it's a good recipe, and since the zucchini is grated, people don't usually realize that's what the green stuff is.)