In a large pot or dutch oven, heat oil over medium-high heat. Add the diced onions, bell peppers, poblano pepper, zucchini, and garlic. Season, to taste, with kosher salt and pepper. Saute, stirring occasionally, until vegetables are tender. Turn heat down to low when they are tender.
Meanwhile, in a large skillet over medium-high heat, Add your meat and season with plenty of salt and pepper for flavor. Cook, while breaking up the meat with the back of a spoon, until it is no longer pink. Drain off excess fat then add cooked meat into the pot with the sauteed veggies.
Add the tomato sauce, diced tomatoes, beef broth, chili powder, and paprika to the pot. Turn heat to medium and bring to a boil, then reduce heat so that the chili is just simmering.
Simmer, uncovered and stirring occasionally, for at least 1 hour (I sometimes cook it for up to 4 hours, the longer the better!). The chili should reduce a bit and thicken (if you like yours more soupy, simmer it covered).