Add chicken to a large ziplock bag with olive oil, lemon juice, oregano, garlic powder, salt and pepper. Shake to combine.
Pre-heat oven to 400 degrees and line a large rimmed baking sheet with foil and brush with olive oil.
Place each spaghetti squash half cut side down onto foil.
Bake for 15 minutes, then remove sheet pan from oven.
Add tomatoes and artichokes to the same sheet pan; drizzle with olive oil, salt, pepper, and thyme. Return to the oven for 25-30 more minutes, or until squash is cooked and tomatoes and artichokes are nicely roasted.
If you are making your own basil, now is the time to do so by adding all ingredients to your blender or food processor and blending until smooth. Store in the fridge until you are ready to serve.
To make the chicken, heat up 1-2 T of olive oil in a large non-stick skillet. When oil is hot, add chicken and cook for 7-8 minutes per side (depending on the size of your chicken). When chicken is cooked, wrap in foil and let rest until you are ready to serve or assemble.
To assemble the bowls, separate the spaghetti squash into strands using a fork and add to each bowl or container. Top with tomatoes, artichokes, chicken, and a dollop of pesto.