I feed my russian tortoise a mix of greens and butternut squash. The butter nut squash is the highest in calcium.
Their favorite are dandelion leaves and they will feast on them till they explode.
I buy all my greens and squash in bulk then chop it up,mix it then frees it in ziplock bags. So i just have to scoop out the right amount every day.
The only other things i add are calcium with d3 and a dash of tortoise topper.

The funny thing is i found this tortoise walking down my street. And nobody claimed it so im keeping her. I set her up in a 90 gallon aquarium with 6 inches of dirt/sand mix and some bricks that make an underground cave where she spends all her time. I have under tank heating and a ceramic heat bulb because she likes to bask after eating. The aquarium sits in my basement window where she gets full sunlight all day.

They will recognize the shorter daylight hours and this will kick off hibernation and they might stop eating. I use a uvb light and timer and give her an extra few hours of daylight every day. Works out great