Mix all spices in a small bowl: hot chili powder, sweet smoked paprika, cumin, garlic powder, and oregano.
Make fajitas veggies
Peel the onion. Cut-off a little bit from both ends (stem and roots part). Then, cut it in half. Now, place the half onion on its flat side and make horizontal cuts. I usually cut it as thin as the width of an onion layer.
Wash the pepper. Lay it on its side and cut off the stem. Now, cut it in half and take the seeds out. Now, place the half pepper on its open flat side and make horizontal cuts of ¼-inch (4-5 mm) wide.
Place a parchment paper in a sheet pan and place the prepared fajitas veggie strips on it
Sprinkle them with olive oil and season them with half of the spice mix plus salt and pepper. Mix them with tongs.
Roast them in a pre-heated oven of 430 Fahrenheit (220 degrees Celcius).
After 10 minutes, take the sheet pan out, turn the veggies with tongs and sprinkle them with the other half of the spice mix. Roast them for 10 more minutes.
Use sheet pan with parchment paper. We recommend sheet pan because it has sides. If you use a baking sheet, the juices from the veggies during roasting might not flow off of it.
Cut veggies in equal strips. This is to make sure the vegetables are ready at the same time.
Place veggies in batches on the sheet pan. If they are grouped together, they will be easier to mix and match and serve.
Hot and sweet together? – In case you prepare the veggies for kids or for people who don’t like spicy food, roast hot chili peppers separate from all other veggies. If you roast hot chili peppers and bell peppers together, the juices of the hot chili peppers may make the sweet bell peppers also spicy and hot.
Other ways to make fajitas veggies. After preparing and cutting your veggies you can use other ways to get them ready like 1) Sautee them in a cast-iron skillet or grill pan* or griddle or 2) Grill them in aluminum foil drip pans* on your BBQ.