Saute onion in oil in large skillet, stirring often, until soft and golden, about 8 minutes. Add red pepper and cook 4 minutes longer. Add spinach, lemon rind, salt, sugar and pepper.
Transfer to medium size bowl. Stir in ricotta cheese. Set aside. Preheat oven to 400 degrees. Grease bottom of 15.5 x 10.5 inch jelly roll pan. Line bottom with wax paper.
Add the salt and garlic, stirring well. Remove from the heat and stir in the ground chile and oregano, coating the meat evenly with the spices. (If you are using a combination of mild and hot chile, do not add the hot spice yet.) Add a small amount of broth and stir well.
Return to the heat, add a bit more broth and stir. Continue to add broth, a little at a time, stirring, until the chili is smooth, then reduce the heat and simmer, uncovered, for about 1 hour.
Taste and adjust seasonings adding the ground hot chile to taste at this point. To add, remove the pot from the heat, sprinkle the chile over the top, and stir well.
Serve the chili with a bowl of freshly stewed pinto beans on the side.