Preheat oven to 450° with racks in top and bottom thirds, and a baking sheet on each rack.
Toss cauliflower with 1 Tbsp.oil and thyme; season with salt
and pepper and arrange in a single layer on baking sheet from bottom rack, then return to oven.
Toss carrots with 1 Tbsp. oil and 1/2 tsp. cumin; season with salt
and pepper and arrange in a single layer on baking sheet from top rack, then return to oven.
Roast cauliflower and carrots until tender, about 20 minutes, turning once.
Heat 2 cups water and salt in a saucepan to a boil; stir in freekeh, cover, and reduce heat to medium- low. Simmer freekeh until liquid is absorbed, about 20 minutes.
Remove freekeh from heat, let stand 5 minutes, then divide among four bowls.
Whisk together tahini, 1/3 cup water, lemon juice, remaining 1 Tbsp. oil, honey, garlic, and 1/4 tsp. cumin for the dressing; season with salt and pepper.
Top bowls of freekeh with spinach, avocados, carrots, cauliflower, and pepitas; drizzle with dressing.